for Journals by Title or ISSN
for Articles by Keywords
Journal Cover Sports
  [2 followers]  Follow
  This is an Open Access Journal Open Access journal
   ISSN (Online) 2075-4663
   Published by MDPI Homepage  [202 journals]
  • Sports, Vol. 6, Pages 1: The Three-Month Effects of a Ketogenic Diet on
           Body Composition, Blood Parameters, and Performance Metrics in CrossFit
           Trainees: A Pilot Study

    • Authors: Wesley Kephart, Coree Pledge, Paul Roberson, Petey Mumford, Matthew Romero, Christopher Mobley, Jeffrey Martin, Kaelin Young, Ryan Lowery, Jacob Wilson, Kevin Huggins, Michael Roberts
      First page: 1
      Abstract: Adopting low carbohydrate, ketogenic diets remains a controversial issue for individuals who resistance train given that this form of dieting has been speculated to reduce skeletal muscle glycogen levels and stifle muscle anabolism. We sought to characterize the effects of a 12-week ketogenic diet (KD) on body composition, metabolic, and performance parameters in participants who trained recreationally at a local CrossFit facility. Twelve participants (nine males and three females, 31 ± 2 years of age, 80.3 ± 5.1 kg body mass, 22.9 ± 2.3% body fat, 1.37 back squat: body mass ratio) were divided into a control group (CTL; n = 5) and a KD group (n = 7). KD participants were given dietary guidelines to follow over 12 weeks while CTL participants were instructed to continue their normal diet throughout the study, and all participants continued their CrossFit training routine for 12 weeks. Pre, 2.5-week, and 12-week anaerobic performance tests were conducted, and pre- and 12-week tests were performed for body composition using dual X-ray absorptiometry (DXA) and ultrasound, resting energy expenditure (REE), blood-serum health markers, and aerobic capacity. Additionally, blood beta hydroxybutyrate (BHB) levels were measured weekly. Blood BHB levels were 2.8- to 9.5-fold higher in KD versus CTL throughout confirming a state of nutritional ketosis. DXA fat mass decreased by 12.4% in KD (p = 0.053). DXA total lean body mass changes were not different between groups, although DXA dual-leg lean mass decreased in the KD group by 1.4% (p = 0.068), and vastus lateralis thickness values decreased in the KD group by ~8% (p = 0.065). Changes in fasting glucose, HDL cholesterol, and triglycerides were similar between groups, although LDL cholesterol increased ~35% in KD (p = 0.048). Between-group changes in REE, one-repetition maximum (1-RM) back squat, 400 m run times, and VO2peak were similar between groups. While our n-sizes were limited, these preliminary data suggest that adopting a ketogenic diet causes marked reductions in whole-body adiposity while not impacting performance measures in recreationally-trained CrossFit trainees. Whether decrements in dual-leg muscle mass and vastus lateralis thickness in KD participants were due to fluid shifts remain unresolved, and increased LDL-C in these individuals warrants further investigation.
      Citation: Sports
      PubDate: 2018-01-09
      DOI: 10.3390/sports6010001
      Issue No: Vol. 6, No. 1 (2018)
  • Sports, Vol. 5, Pages 72: Influence of Dynamic Strength Index on
           Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time

    • Authors: John McMahon, Paul Jones, Thomas Dos’Santos, Paul Comfort
      First page: 72
      Abstract: The dynamic strength index (DSI), often calculated as the ratio of countermovement jump (CMJ) propulsion peak force to isometric mid-thigh pull (IMTP) peak force, is said to inform whether ballistic or maximal strength training is warranted for a given athlete. CMJ propulsion peak force is highly influenced by jump strategy, however, which is not highlighted by the DSI alone. This study aimed to quantitatively compare CMJ force-, power-, velocity-, and displacement-time curves between athletes who achieved high versus low DSI scores. Fifty-three male collegiate athletes performed three CMJs and IMTPs on a force platform. Athletes were ranked based on DSI score and the CMJ kinetic and kinematic-time curves of the bottom and top twenty athletes were compared. The low DSI group (0.55 ± 0.10 vs. 0.92 ± 0.11) produced greater IMTP peak force (46.7 ± 15.0 vs. 31.1 ± 6.6 N·kg−1) but a larger braking net impulse in the CMJ, leading to greater braking velocity and larger countermovement displacement. This strategy resulted in a similar CMJ propulsion peak force (25.9 ± 2.2 vs. 25.4 ± 3.1 N·kg−1) to the high DSI group. These results, taken together with those of previous studies, support the notion of ballistic versus maximal strength training likely being better suited to low versus high DSI scorers, respectively.
      Citation: Sports
      PubDate: 2017-09-23
      DOI: 10.3390/sports5040072
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 73: Executive Function and the P300 after Treadmill
           Exercise and Futsal in College Soccer Players

    • Authors: Junyeon Won, Shanshan Wu, Hongquing Ji, J. Smith, Jungjun Park
      First page: 73
      Abstract: (1) Background: Although a body of evidence demonstrates that acute exercise improves executive function, few studies have compared more complex, laboratory-based modes of exercise, such as soccer that involve multiple aspects of the environment. (2) Methods: Twelve experienced soccer players (24.8 ± 2 years) completed three counterbalanced 20 min sessions of (1) seated rest; (2) moderate intensity treadmill exercise; and (3) a game of futsal. Once heart rate returned to within 10% of pre-activity levels, participants completed the Stroop Color Word Conflict Task while reaction time (RT) and P300 event-related potentials were measured. (3) Results: Reaction time during Stroop performance was significantly faster following the futsal game and treadmill exercise compared to the seated rest. The P300 amplitude during Stroop performance was significantly greater following futsal relative to both treadmill and seated-rest conditions. (4) Conclusions: These findings suggest that single bouts of indoor soccer among college-aged soccer players, compared to treadmill and seated-rest conditions, may engender the greatest effect on brain networks controlling attention allocation and classification speed during the performance of an inhibitory control task. Future research is needed to determine if cognitively engaging forms of aerobic exercise may differentially impact executive control processes in less experienced and older adult participants.
      Citation: Sports
      PubDate: 2017-09-26
      DOI: 10.3390/sports5040073
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 74: The Relationship between Actual Fundamental
           Motor Skill Proficiency, Perceived Motor Skill Confidence and Competence,
           and Physical Activity in 8–12-Year-Old Irish Female Youth

    • Authors: Orlagh Farmer, Sarahjane Belton, Wesley O’Brien
      First page: 74
      Abstract: This study examines the relationship between actual fundamental motor skill (FMS) proficiency, perceived motor confidence and competence, and physical activity (PA) among female children (n= 160; mean age = 10.69 ± 1.40 years). The Test of Gross Motor Development-2nd Edition (TGMD-2) was used to assess seven FMSs (locomotor, object-control, and stability). Motor confidence and competence were assessed using a valid skill-specific scale, and a modified version of the Self-Perception Profile for Children. PA levels were assessed using self-report (PA Questionnaire for Older Children (PAQ-C)) and classified as low, moderate, and high active. One-way and two-way ANOVAs (post-hoc honest significant difference (HSD)) and correlation coefficients were used to analyse the data. Findings indicate that the majority of youth (71.8%) were not meeting the minimum 60 min of daily PA recommended for health, and that 98.1% did not achieve the FMS proficiency expected for their age. While there were high levels of perceived physical self-confidence (PSC) reported within FMS skill-specific tasks, there was no significant correlation observed between actual FMS proficiency and perceived PSC among the cohort. Results show that low, moderately, and highly active female participants differ significantly in terms of their overall FMS (p = 0.03) and locomotor (LOC) control scores (p = 0.03). Results from a two-way between-groups analysis of variance also revealed no statistically significant interaction effect between PA grouping and physical performance self-concept (PPSC) on overall FMS proficiency levels. Results of a multiple linear regression indicate that perceived PSC is a significant predictor (beta = 0.183) of participants’ overall PA levels. Data show a need for targeting low levels of PA, and low FMS proficiency in female youth, and for developing interventions aiming to enhance perceived PSC levels.
      Citation: Sports
      PubDate: 2017-09-27
      DOI: 10.3390/sports5040074
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 75: To Take the Stairs or Not to Take the
           Stairs' Employing the Reflective–Impulsive Model to Predict
           Spontaneous Physical Activity

    • Authors: Marcos Daou, Keith Lohse, Matthew Miller
      First page: 75
      Abstract: The reflective–impulsive model (RIM) has been employed to explain various health behaviors. The present study used RIM to predict a spontaneous physical activity behavior. Specifically, 107 participants (75 females; Mage = 20.6 years, SD = 1.92 years) completed measures of (1) reflections about spontaneous physical activity, as indexed by self-report questionnaire; (2) impulse toward physical activity, as indexed by the manikin task; and (3) (state) self-control, as indexed by the Stroop task. The dependent variable was whether participants took the stairs or the elevator to the study laboratory. Results revealed reflections toward spontaneous physical activity positively predicted stair-taking. Further, a significant impulse toward physical activity × self-control interaction was observed. This interaction revealed that participants with high self-control who had a high impulse toward PA were more likely to take the stairs than their counterparts with a low impulse toward PA, whereas the opposite was the case for participants with low self-control. However, the impulse × self-control interaction was not significant when employing a self-report measure of trait self-control. Thus, RIM may be a good framework with which to consider spontaneous physical activity, but careful consideration must be given when examining variables within RIM (e.g., the boundary condition of self-control).
      Citation: Sports
      PubDate: 2017-09-29
      DOI: 10.3390/sports5040075
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 76: Do Bodybuilders Use Evidence-Based Nutrition
           Strategies to Manipulate Physique'

    • Authors: Lachlan Mitchell, Daniel Hackett, Janelle Gifford, Frederico Estermann, Helen O’Connor
      First page: 76
      Abstract: Competitive bodybuilders undergo strict dietary and training practices to achieve an extremely lean and muscular physique. The purpose of this study was to identify and describe different dietary strategies used by bodybuilders, their rationale, and the sources of information from which these strategies are gathered. In-depth interviews were conducted with seven experienced (10.4 ± 3.4 years bodybuilding experience), male, natural bodybuilders. Participants were asked about training, dietary and supplement practices, and information resources for bodybuilding strategies. Interviews were transcribed verbatim and analyzed using qualitative content analysis. During the off-season, energy intake was higher and less restricted than during the in-season to aid in muscle hypertrophy. There was a focus on high protein intake with adequate carbohydrate to permit high training loads. To create an energy deficit and loss of fat mass, energy intake was gradually and progressively reduced during the in-season via a reduction in carbohydrate and fat intake. The rationale for weekly higher carbohydrate refeed days was to offset declines in metabolic rate and fatigue, while in the final “peak week” before competition, the reasoning for fluid and sodium manipulation and carbohydrate loading was to enhance the appearance of leanness and vascularity. Other bodybuilders, coaches and the internet were significant sources of information. Despite the common perception of extreme, non-evidence-based regimens, these bodybuilders reported predominantly using strategies which are recognized as evidence-based, developed over many years of experience. Additionally, novel strategies such as weekly refeed days to enhance fat loss, and sodium and fluid manipulation, warrant further investigation to evaluate their efficacy and safety.
      Citation: Sports
      PubDate: 2017-09-29
      DOI: 10.3390/sports5040076
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 77: The Age-Related Association of Movement in Irish
           Adolescent Youth

    • Authors: Diarmuid Lester, Bronagh McGrane, Sarahjane Belton, Michael Duncan, Fiona Chambers, Wesley O’Brien
      First page: 77
      Abstract: (1) Background: Research has shown that post-primary Irish youth are insufficiently active and fail to reach a level of proficiency across basic movement skills. The purpose of the current research was to gather cross-sectional baseline data on Irish adolescent youth, specifically the prevalence of movement skills and patterns, in order to generate an overall perspective of movement within the first three years (Junior Certificate level) of post-primary education. (2) Methods: Data were collected on adolescents (N = 181; mean age: 14.42 ± 0.98 years), attending two, mixed-gender schools. Data collection included 10 fundamental movement skills (FMS) and the seven tests within the Functional Movement Screen (FMS™). The data set was analysed using the Statistical Package for Social Sciences (SPSS) version 20.0 for Windows. (3) Results: Overall, levels of actual mastery within fundamental and functional movement were low. There were statistically significant age-related differences observed, with a progressive decline as age increased in both the object control (p = 0.002) FMS sub-domain, and the in-line lunge (p = 0.048) test of the FMS™. (4) Conclusion: In summary, we found emerging evidence that school year group is significantly associated with mastery of movement skills and patterns. Results from the current study suggest that developing a specifically tailored movement-oriented intervention would be a strategic step towards improving the low levels of adolescent fundamental and functional movement proficiency.
      Citation: Sports
      PubDate: 2017-10-02
      DOI: 10.3390/sports5040077
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 78: Maximum Strength, Rate of Force Development,
           Jump Height, and Peak Power Alterations in Weightlifters across Five
           Months of Training

    • Authors: W. Hornsby, Jeremy Gentles, Christopher MacDonald, Satoshi Mizuguchi, Michael Ramsey, Michael Stone
      First page: 78
      Abstract: The purpose of this monitoring study was to investigate how alterations in training affect changes in force-related characteristics and weightlifting performance. Subjects: Seven competitive weightlifters participated in the study. Methods: The weightlifters performed a block style periodized plan across 20 weeks. Force plate data from the isometric mid-thigh pull and static jumps with 0 kg, 11 kg, and 20 kg were collected near the end of each training block (weeks 1, 6, 10, 13, 17, and 20). Weightlifting performance was measured at weeks 0, 7, 11, and 20. Results: Very strong correlations were noted between weightlifting performances and isometric rate of force development (RFD), isometric peak force (PF), peak power (PP), and jump height (JH). Men responded in a more predictable manner than the women. During periods of higher training volume, RFD was depressed to a greater extent than PF. JH at 20 kg responded in a manner reflecting the expected fatigue response more so than JH at 0 kg and 11 kg. Conclusions: PF appears to have been more resistant to volume alterations than RFD and JH at 20 kg. RFD and JH at 20 kg appear to be superior monitoring metrics due to their “sensitivity.”
      Citation: Sports
      PubDate: 2017-10-13
      DOI: 10.3390/sports5040078
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 79: Quality of Life and Breast Cancer: How Can
           Mind–Body Exercise Therapies Help' An Overview Study

    • Authors: Anne Husebø, Tormod Husebø
      First page: 79
      Abstract: Breast cancer survivors experience extensive treatments, threatening their quality of life. Complementary therapies used as a supplement to cancer treatment may control symptoms, enhance quality of life, and contribute to overall patient care. Mind–body exercise therapies might motivate cancer survivors to exercise, and assist them in regaining health. The purpose of this overview study is to study benefits from mind–body exercise of yoga, tai chi chuan and qigong upon quality of life in breast cancer populations. A systematic overview of reviews was applied. Literature search in five electronic databases and in reference lists was performed during April 2017. In addition, experts in the field were consulted. Of 38 identified titles, 11 review articles, including six meta-analyses were found eligible for review. Methodological quality was high for the majority of quality domains. Yoga, the most studied mind–body therapy, was found to benefit breast cancer patients’ psychological quality of life, while less support was established concerning physical quality of life elements. The evidence of improvements of quality of life from tai chi chuan and qigong remains unclear. Breast cancer survivors’ experiences of psychological and social well-being may be enhanced by practicing yoga.
      Citation: Sports
      PubDate: 2017-10-13
      DOI: 10.3390/sports5040079
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 80: Red Spinach Extract Increases Ventilatory
           Threshold during Graded Exercise Testing

    • Authors: Angelique Moore, Cody Haun, Wesley Kephart, Angelia Holland, Christopher Mobley, David Pascoe, Michael Roberts, Jeffrey Martin
      First page: 80
      Abstract: Background: We examined the acute effect of a red spinach extract (RSE) (1000 mg dose; ~90 mg nitrate (NO 3 − )) on performance markers during graded exercise testing (GXT). Methods: For this randomized, double-blind, placebo (PBO)-controlled, crossover study, 15 recreationally-active participants (aged 23.1 ± 3.3 years; BMI: 27.2 ± 3.7 kg/m2) reported >2 h post-prandial and performed GXT 65–75 min post-RSE or PBO ingestion. Blood samples were collected at baseline (BL), pre-GXT (65–75 min post-ingestion; PRE), and immediately post-GXT (POST). GXT commenced with continuous analysis of expired gases. Results: Plasma concentrations of NO 3 − increased PRE (+447 ± 294%; p < 0.001) and POST (+378 ± 179%; p < 0.001) GXT with RSE, but not with PBO (+3 ± 26%, −8 ± 24%, respectively; p > 0.05). No effect on circulating nitrite (NO 2 − ) was observed with RSE (+3.3 ± 7.5%, +7.7 ± 11.8% PRE and POST, respectively; p > 0.05) or PBO (−0.5 ± 7.9%, −0.2 ± 8.1% PRE and POST, respectively; p > 0.05). When compared to PBO, there was a moderate effect of RSE on plasma NO 2 − at PRE (g = 0.50 [−0.26, 1.24] and POST g = 0.71 [−0.05, 1.48]). During GXT, VO2 at the ventilatory threshold was significantly higher with RSE compared to PBO (+6.1 ± 7.3%; p < 0.05), though time-to-exhaustion (−4.0 ± 7.7%; p > 0.05) and maximal aerobic power (i.e., VO2 peak; −0.8 ± 5.6%; p > 0.05) were non-significantly lower with RSE. Conclusions: RSE as a nutritional supplement may elicit an ergogenic response by delaying the ventilatory threshold.
      Citation: Sports
      PubDate: 2017-10-16
      DOI: 10.3390/sports5040080
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 81: Organized Sport Participation and Physical
           Activity Levels among Adolescents with Functional Limitations

    • Authors: Kwok Ng, Pauli Rintala, Yeshayahu Hutzler, Sami Kokko, Jorma Tynjälä
      First page: 81
      Abstract: Sufficient and regular physical activity is considered a protective factor, reducing the onset of secondary disability conditions in adolescents with chronic diseases and functional limitations. The aim of this study was to explore whether participation in organized sport may be associated to higher levels of physical activity in adolescents with functional limitations, based on a national representative sample. Data from the Health Behaviour in School-aged Children (HBSC) study collected in Finland from two data collection rounds (2002 and 2010) were conducted and pooled from adolescents aged between 13 and 15 years old with functional limitations (n = 1041). Differences in self-reported physical activity over the past week and participation in organized sport activity were analysed for each function. Overall, four in ten (n = 413) participated in organized sport and were significantly (p < 0.001) more physically active (mean = 4.92days, SD = 1.81) than their non-participating (mean = 3.29, SD = 1.86) peers with functional limitations. Despite low population prevalence, adolescents with epilepsy or visual impairments were the least active if they were not participating in organized sport, yet were the most active if they were involved in organized sport. Participating in organized sport appears to be an important factor promoting resources for maintaining recommended levels of physical activity in Finnish adolescents with functional limitations.
      Citation: Sports
      PubDate: 2017-10-19
      DOI: 10.3390/sports5040081
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 82: Effect of a Hexagonal Barbell on the Mechanical
           Demand of Deadlift Performance

    • Authors: Jason Lake, Freddie Duncan, Matt Jackson, David Naworynsky
      First page: 82
      Abstract: This study compared typical mechanical variables of interest obtained directly from barbell motion during deadlift performance with a conventional (CBD) and a hexagonal barbell (HBD). Eleven men, proficient with both deadlift variations, volunteered to participate in the study (age: 20.3 ± 0.6 years; height: 175.5 ± 8.5 m; mass: 88.7 ± 19.0 kg; CBD 1RM: 183 ± 22 kg; HBD 1RM: 194 ± 20 kg). During the first session, CBD and HBD 1RM was assessed; during the second session, they performed 3 sets of 1 CBD repetition with 90% 1RM; and in session three, they repeated this process with the HBD. Barbell displacement was recorded at 1000 Hz and mechanical parameters derived from this. Significantly heavier loads were lifted during HBD (6%, p = 0.003). There were no significant differences between barbell displacement (p = 0.216). However, HBD was performed significantly faster (15%, p = 0.012), HBD load was accelerated for significantly longer (36%, p = 0.004), and significantly larger mean forces underpinned this (6%, p < 0.001), with more work having been performed (7%, p < 0.001) at greater power outputs (28%, p < 0.001). The results of this study showed that heavier HBD loads can be lifted through the same range of motion faster, and that this load is accelerated for significantly longer. The strategies used to achieve these differences could have a significant effect on training outcomes.
      Citation: Sports
      PubDate: 2017-10-24
      DOI: 10.3390/sports5040082
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 83: Effects of a Six-Week Strength Training

    • Authors: Frank Bourgeois, Paul Gamble, Nic Gill, Mike McGuigan
      First page: 83
      Abstract: This study investigated the effects of eccentric phase-emphasis strength training (EPE) on unilateral strength and performance in 180- and 45-degree change of direction (COD) tasks in rugby union players. A 12-week cross-over design was used to compare the efficacy of resistance training executed with 3 s eccentric duration (EPE, n = 12) against conventional strength training, with no constraints on tempo (CON, n = 6). Players in each condition were categorised as ‘fast’ (FAST) or ‘slow’ (SLOW) using median trial times from baseline testing. Players recorded greater isometric strength improvements following EPE (ES = −0.54 to 1.80). Whilst these changes were not immediate, players improved in strength following cessation. Improvements in 180-degree COD performance was recorded at all test-points following EPE (ES = −1.32 to −0.15). Improvements in 45-degree COD performance were apparent for FAST following CON (ES = −0.96 to 0.10), but CON was deleterious for SLOW (ES = −0.60 to 1.53). Eccentric phase-emphasis strength training shows potential for sustained strength enhancement. Positive performance changes in COD tasks were category- and condition-specific. The data indicate the greatest improvement occurred at nine weeks following resistance training in these players. Performance benefits may also be specific to COD task, player category, and relative to emphasis on eccentric phase activity.
      Citation: Sports
      PubDate: 2017-10-24
      DOI: 10.3390/sports5040083
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 84: Effects of Rule Changes on Game-Related
           Statistics in Men’s Water Polo Matches

    • Authors: Joaquin Madera, Victor Tella, Jose Saavedra
      First page: 84
      Abstract: The aim of this study was to investigate the effects of rule changes on game-related statistics in men’s water polo matches. A total of 856 men’s matches played in all Olympic Games and World Championship since 1936 was analysed. The game-related statistics considered were: total goals, winners’ goals, losers’ goals, goals per minute, goals difference, relationship difference goals and total goals, and relationship difference goals and winners’ goals. The rule changes were grouped by structural (game and period) and functional changes (possession time, exclusion time, timing, minimum distance to take a direct shot). Differences between rule changes were determined using a one-way ANOVA. In general, the changes in water polo rules were shown to have an effect on the final result of the matches. There were differences in each rule change of duration (increased total goals and winners’ goals), period (increased total goals and winners’ goals), possession time (increased losers’ goals), timing (increased total, winners’, losers’, and decreased % goals and total goals) and fouls (increased total goals and losers’ goals). The analysis in game-related statistics through the rule changes could be used to evaluate their effects and/or justify future modifications.
      Citation: Sports
      PubDate: 2017-11-01
      DOI: 10.3390/sports5040084
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 85: Variability of Jump Kinetics Related to Training
           Load in Elite Female Basketball

    • Authors: Jan Legg, David Pyne, Stuart Semple, Nick Ball
      First page: 85
      Abstract: The purpose of this study was to quantify changes in jump performance and variability in elite female basketballers. Junior and senior female representative basketball players (n = 10) aged 18 ± 2 years participated in this study. Countermovement jump (CMJ) data was collected with a Gymaware™ optical encoder at pre-, mid-, and post-season time points across 10 weeks. Jump performance was maintained across the course of the full season (from pre to post). Concentric peak velocity, jump height, and dip showed the most stability from pre- to post-season, with the %CV ranging from 5.6–8.9%. In the period of the highest training load (mid-season), the variability of within-subject performance was reduced by approximately 2–4% in all measures except for jump height. Altered jump mechanics through a small (0.26 effect size) increase in dip were evident at mid-season, suggesting that CMJ analysis is useful for coaches to use as an in-season monitoring tool. The highest coefficient of variation (8–22%CV) in inter-set scores in all measures except eccentric peak velocity also occurred mid-season. It appears that in-season load not only impairs jump performance, but also movement variability in basketball players.
      Citation: Sports
      PubDate: 2017-11-04
      DOI: 10.3390/sports5040085
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 86: Balance Performance as Observed by
           Center-of-Pressure Parameter Characteristics in Male Soccer Athletes and

    • Authors: Lara Thompson, Mehdi Badache, Steven Cale, Lonika Behera, Nian Zhang
      First page: 86
      Abstract: Static balance has a relevant influence on athletic performance as well as on reducing the risk of injury. The main goal of this study was to assess soccer athlete versus non-athlete balance performance via displacement and velocity parameters extracted from the center-of-pressure (COP) position time series. In order to accomplish our goal, we investigated standing balance in two male groups with unimpaired balance: non-athletes (n = 12) and collegiate varsity soccer athletes (n = 12). In order to make the standing balancing task more or less difficult, we altered participant base-of-support, as well as vision, yielding static (quiet stance) test conditions increasing in difficulty. From the COP position time series, displacement and velocity parameters were computed and plotted as a function of increasing test condition difficulty level. COP parameters showed steeper increases with increased test difficulty in non-athletes compared to athletes; this demonstrated athletes’ better ability to control their balance. We concluded that balance performance could be characterized via COP displacement and velocity response curves. This study lends new insights into how COP parameters can be utilized to determine and characterize improvements in balance between un-impaired subject populations (athletes versus non-athletes).
      Citation: Sports
      PubDate: 2017-11-08
      DOI: 10.3390/sports5040086
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 87: Current Research and Statistical Practices in
           Sport Science and a Need for Change

    • Authors: Jake Bernards, Kimitake Sato, G. Haff, Caleb Bazyler
      First page: 87
      Abstract: Current research ideologies in sport science allow for the possibility of investigators producing statistically significant results to help fit the outcome into a predetermined theory. Additionally, under the current Neyman-Pearson statistical structure, some argue that null hypothesis significant testing (NHST) under the frequentist approach is flawed, regardless. For example, a p-value is unable to measure the probability that the studied hypothesis is true, unable to measure the size of an effect or the importance of a result, and unable to provide a good measure of evidence regarding a model or hypothesis. Many of these downfalls are key questions researchers strive to answer following an investigation. Therefore, a shift towards a magnitude-based inference model, and eventually a fully Bayesian framework, is thought to be a better fit from a statistical standpoint and may be an improved way to address biases within the literature. The goal of this article is to shed light on the current research and statistical shortcomings the field of sport science faces today, and offer potential solutions to help guide future research practices.
      Citation: Sports
      PubDate: 2017-11-15
      DOI: 10.3390/sports5040087
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 88: Comparison of the Relationship between Lying and
           Standing Ultrasonography Measures of Muscle Morphology with Isometric and
           Dynamic Force Production Capabilities

    • Authors: John Wagle, Kevin Carroll, Aaron Cunanan, Christopher Taber, Alexander Wetmore, Garett Bingham, Brad DeWeese, Kimitake Sato, Charles Stuart, Michael Stone
      First page: 88
      Abstract: The purpose of the current study was (1) to examine the differences between standing and lying measures of vastus lateralis (VL), muscle thickness (MT), pennation angle (PA), and cross-sectional area (CSA) using ultrasonography; and (2) to explore the relationships between lying and standing measures with isometric and dynamic assessments of force production—specifically peak force, rate of force development (RFD), impulse, and one-repetition maximum back squat. Fourteen resistance-trained subjects (age = 26.8 ± 4.0 years, height = 181.4 ± 6.0 cm, body mass = 89.8 ± 10.7 kg, back squat to body mass ratio = 1.84 ± 0.34) agreed to participate. Lying and standing ultrasonography images of the right VL were collected following 48 hours of rest. Isometric squat assessments followed ultrasonography, and were performed on force platforms with data used to determine isometric peak force (IPF), as well as RFD and impulse at various time points. Forty-eight hours later, one-repetition maximum back squats were performed by each subject. Paired-samples t-tests revealed statistically significant differences between standing and lying measurements of MT (p < 0.001), PA (p < 0.001), and CSA (p ≤ 0.05), with standing values larger in all cases. Further, standing measures were correlated more strongly and abundantly to isometric and dynamic performance. These results suggest that if practitioners intend to gain insight into strength-power potential based on ultrasonography measurements, performing the measurement collection with the athlete in a standing posture may be preferred.
      Citation: Sports
      PubDate: 2017-11-21
      DOI: 10.3390/sports5040088
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 89: Four Weeks of Off-Season Training Improves Peak
           Oxygen Consumption in Female Field Hockey Players

    • Authors: Lindsey Funch, Erik Lind, Larissa True, Deborah Van Langen, John Foley, James Hokanson
      First page: 89
      Abstract: The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak) and running economy (RE) following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years) were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8) and High Intensity Interval Training (HIIT; n = 6). Participants completed 12 training sessions. HITrun consisted of 30 min of high-intensity running, while HIIT consisted of a series of whole-body high intensity Tabata-style intervals (75–85% of age predicted maximum heart rate) for a total of four minutes. In addition to the interval training, the off-season training included six resistance training sessions, three team practices, and concluded with a team scrimmage. V ˙O2peak was measured pre- and post-training to determine the effectiveness of the training program. A two-way mixed (group × time) ANOVA showed a main effect of time with a statistically significant difference in V ˙O2peak from pre- to post-testing, F(1, 12) = 12.657, p = 0.004, partial η2 = 0.041. Average (±SD) V ˙O2peak increased from 44.64 ± 3.74 to 47.35 ± 3.16 mL·kg−1·min−1 for HIIT group and increased from 45.39 ± 2.80 to 48.22 ± 2.42 mL·kg−1·min−1 for HITrun group. Given the similar improvement in aerobic power, coaches and training staff may find the time saving element of HIIT-type conditioning programs attractive.
      Citation: Sports
      PubDate: 2017-11-28
      DOI: 10.3390/sports5040089
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 90: Interrepetition Rest Set Lacks the V-Shape
           Systolic Pressure Response Advantage during Resistance Exercise

    • Authors: Xian Mayo, Eliseo Iglesias-Soler, J. Kingsley, Xurxo Dopico
      First page: 90
      Abstract: Resistance exercise may lead to an aneurysm due to dangerous levels of systemic hypertension. Thus, a minimized pressure response during exercise may guarantee safer training. For that, we analyzed an interrepetition rest design (IRD) hypothesizing that it would produce a lower systolic blood pressure (SBP) response in comparison with a continuous design (CD). Additionally, we studied the effect of accumulated repetitions on the increasing SBP rate during the first continuous set. Fifteen healthy participants (age: 24 ± 2 years; SBP: 113 ± 8 mmHg) performed leg presses, with 40 repetitions and 720 s of total rest, structured in an IRD of individual repetitions (resting time: 18.5 s), and in a CD of five sets of eight repetitions (resting time: 180 s). Analyses reported an increase (p = 0.013) in the mean peaks of SBP in the IRD (162 ± 21 mmHg), versus the CD (148 ± 19 mmHg), while both augmented versus baselines (p < 0.001). Additionally, the linear model estimated a progressive increase of SBP of around 7 mmHg per repetition. Summarily, the IRD produced a higher mean of the SBP peaks during the 40 repetitions due to lacking the v-shape advantage in comparison with the CD.
      Citation: Sports
      PubDate: 2017-12-01
      DOI: 10.3390/sports5040090
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 91: The Relationship between Trail Running
           Withdrawals and Race Topography

    • Authors: Antonini Roberta, Rochat Nadège, Crettaz Fabienne, Hauw Denis
      First page: 91
      Abstract: Context: A growing amount of recent research in sport psychology has focused on trying to understand withdrawals from ultra-races. However, according to the Four E approach, the studies underestimated the embedded components of these experiences and particularly how they were linked to the specific environmental conditions in which the experiences occurred. Objective: This study aimed to characterize trail running withdrawals in relationship to race topography. Design: Qualitative design, involving self-confrontation interviews and use of a race map. Setting: Use of the race map for description of the race activity and self-confrontation interviews took place 1–3 days after the races. Participants: Ten runners who withdrew during an ultra-trail race. Data Collection and Analysis: Data on past activity traces and experiences were elicited from self-confrontation interviews. Data were coded and compared to identify common sequences and then each type of sequence was counted with regard to race topography. Results: Results showed that each sequence was related to runners’ particular possibilities for acting, feeling, and thinking, which were in turn embedded in the race topography. These sequences allowed the unfolding of the activity and increased its overall effectiveness in relation to the constraints of this specific sport. Conclusion: This study allowed us to highlight important information on how ultra-trail runners manage their races in relationship to the race environment and more specifically to its topography. The result will also help us to recommend potential adjustments to ultra-trail runners’ performance-oriented training and preparation.
      Citation: Sports
      PubDate: 2017-12-05
      DOI: 10.3390/sports5040091
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 92: The Relative Age Effect, Height and Weight
           Characteristics among Lower and Upper Secondary School Athletes in Norway
           and Sweden

    • Authors: Stig Sæther, Tomas Peterson, Vazjwar Matin
      First page: 92
      Abstract: The relative age effect (RAE) has been found among youth elite athletes within a range of sports. However, the RAE has been studied to a lesser degree among youth non-elite athletes, and even less among school pupils attending sport specialisation programmes (SSPs). The aim of the present study was to investigate RAE, height, and weight, and compare Swedish lower secondary school and Norwegian upper secondary school pupils. Study 1 includes 156 lower secondary school athletes (95 boys and 61 girls) following an SSP in Sweden, while study 2 includes 111 upper secondary school athletes (81 boys and 30 girls) from two Norwegian schools. The RAE was found in both male groups, but only in Swedish girls. Furthermore, the relationship between birth month, height, and weight was found to be non-significant. These results indicate a vital RAE effect among youth non-elite athletes attending SSPs in both lower and upper secondary schools.
      Citation: Sports
      PubDate: 2017-12-08
      DOI: 10.3390/sports5040092
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 93: Erratum: Robinson, L.E., et al. Development of a
           Digital-Based Instrument to Assess Perceived Motor Competence in Children:
           Face Validity, Test–Retest Reliability, and Internal Consistency. Sports
           2017, 5, 48

    • Authors: Sports Editorial Office
      First page: 93
      Abstract: The editorial team of the journal Sports would like to make the following corrections to the published paper [...]
      Citation: Sports
      PubDate: 2017-12-08
      DOI: 10.3390/sports5040093
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 94: Residents of Central Queensland, Australia Are
           Aware of Healthy Eating Practices but Consume Unhealthy Diets

    • Authors: Vincent Dalbo, Matthew Hiskens, Masaru Teramoto, Michael Kingsley, Kaelin Young, Aaron Scanlan
      First page: 94
      Abstract: We aimed to determine nutritional knowledge and behaviors of normal weight, overweight, and obese residents of Central Queensland, Australia. Data were collected as part of the 2010 Central Queensland Social Survey (N = 1289). Residents were asked questions assessing nutritional knowledge and behaviors. Statistical analyses were performed to examine differences in nutritional knowledge and behaviors by body mass index (BMI) classification: normal weight, overweight, and obese. Independent of BMI, residents ate fewer than the recommended daily servings of vegetables (p < 0.05) and fruits (p < 0.05) with no differences found between BMI classifications. Overweight (OR: 1.52; 95% CI: 1.13–2.04) and obese (OR: 1.43; 95% CI: 1.04–1.98) residents were more likely to have eaten fast food the week of the survey than normal weight residents. Residents correctly identified the amount of kilocalories required to maintain current body weight with no differences between BMI classifications. Each BMI classification underestimated the amount of kilojoules required to maintain current body weight (p < 0.05). Nutritional knowledge may not be the limiting factor preventing residents from making proper nutritional choices.
      Citation: Sports
      PubDate: 2017-12-11
      DOI: 10.3390/sports5040094
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 95: Changes in Self-Reported Concussion History
           after Administration of a Novel Concussion History Questionnaire in
           Collegiate Recreational Student-Athletes

    • Authors: Adam Copp, Monica Lininger, Meghan Warren
      First page: 95
      Abstract: Research has shown that exposure to a concussion definition (CD) increases self-reported concussion history (SRCH) immediately, however, no research has been performed that examines the effects of exposure to a CD on SRCH over time. Collegiate recreational student-athletes (RSAs) have limited access to monitoring and supervision by medical staff. As such, recognition of concussion symptoms and need for medical management oftentimes falls upon the RSA. The purpose of this study was to assess the effect of a novel questionnaire on the SRCH of RSAs. A two-part questionnaire was sent to RSAs participating is sports with a greater than average risk of concussion at a university in Arizona. Data from 171 RSAs were analyzed to assess the change in RSAs’ suspected concussion estimates pre- and post-exposure to a CD and concussion symptom worksheet, as well as over the short-term (2.5 months). Approximately one-third of RSAs reported an increase in suspected concussion estimates immediately following exposure to the questionnaire, but the change was not maintained over the short-term. The results suggest that a single exposure to a CD is ineffective at increasing short-term SRCH estimates.
      Citation: Sports
      PubDate: 2017-12-17
      DOI: 10.3390/sports5040095
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 96: Team Performance Indicators Explain Outcome
           during Women’s Basketball Matches at the Olympic Games

    • Authors: Anthony Leicht, Miguel Gomez, Carl Woods
      First page: 96
      Abstract: The Olympic Games is the pinnacle international sporting competition with team sport coaches interested in key performance indicators to assist the development of match strategies for success. This study examined the relationship between team performance indicators and match outcome during the women’s basketball tournament at the Olympic Games. Team performance indicators were collated from all women’s basketball matches during the 2004–2016 Olympic Games (n = 156) and analyzed via linear (binary logistic regression) and non-linear (conditional interference (CI) classification tree) statistical techniques. The most parsimonious linear model retained “defensive rebounds”, “field-goal percentage”, “offensive rebounds”, “fouls”, “steals”, and “turnovers” with a classification accuracy of 85.6%. The CI classification tree retained four performance indicators with a classification accuracy of 86.2%. The combination of “field-goal percentage”, “defensive rebounds”, “steals”, and “turnovers” provided the greatest probability of winning (91.1%), while a combination of “field-goal percentage”, “steals”, and “turnovers” provided the greatest probability of losing (96.7%). Shooting proficiency and defensive actions were identified as key team performance indicators for Olympic female basketball success. The development of key defensive strategies and/or the selection of athletes highly proficient in defensive actions may strengthen Olympic match success. Incorporation of non-linear analyses may provide teams with superior/practical approaches for elite sporting success.
      Citation: Sports
      PubDate: 2017-12-17
      DOI: 10.3390/sports5040096
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 97: Associations between Thermal and Physiological
           Responses of Human Body during Exercise

    • Authors: Suleyman Zora, Gorkem Balci, Muzaffer Colakoglu, Tahsin Basaran
      First page: 97
      Abstract: In this study, thermal behaviours of the athletes were investigated with respect to thermal comfort and exercise intensity. The relationship between an index for analysing thermal comfort (Predicted Mean Vote: PMV) and Rating of Perceived Exertion (RPE) which shows exercise intensity and exhaustion level was evaluated. Eleven moderately trained male athletes ( V ˙ O2max 54 ± 9.9 mL∙min−1∙kg−1) had volunteered for the study (age: 22.2 ± 3.7 years; body mass: 73.8 ± 6.9 kg; height: 181 ± 6.3 cm; Body surface area (BSA): 1.93 ± 0.1 m2; body fat: 12.6% ± 4.2%; V ˙ O2max: 54 ± 9.9 mL∙min−1∙kg−1). Experiments were carried out by using a cycle ergometer in an air-conditioned test chamber which provided fresh air and had the ability to control the temperature and relative humidity. The study cohort was divided into two groups according to maximal oxygen consumption levels of the participants. Statistical analyses were conducted with the whole study cohort as well as the two separated groups. There was a moderate correlation between PMV and RPE for whole cohort (r: −0.51). When the whole cohort divided as low and high aerobic power groups, an average correlation coefficient at high oxygen consumption cohort decreased to r: −0.21, while the average correlation coefficient at low oxygen consumption cohort increased to r: −0.77. In conclusion, PMV and RPE have a high correlation in less trained participants, but not in the more trained ones. The case may bring to mind that thermal distribution may be better in high aerobic power group in spite of high RPE and thus the relation between PMV and RPE is affected by exercise performance status.
      Citation: Sports
      PubDate: 2017-12-19
      DOI: 10.3390/sports5040097
      Issue No: Vol. 5, No. 4 (2017)
  • Sports, Vol. 5, Pages 46: An Investigation of the Mechanics and Sticking
           Region of a One-Repetition Maximum Close-Grip Bench Press versus the
           Traditional Bench Press

    • Authors: Robert Lockie, Samuel Callaghan, Matthew Moreno, Fabrice Risso, Tricia Liu, Alyssa Stage, Samantha Birmingham-Babauta, John Stokes, Dominic Giuliano, Adrina Lazar, DeShaun Davis, Ashley Orjalo
      First page: 46
      Abstract: The close-grip bench press (CGBP) is a variation of the traditional bench press (TBP) that uses a narrower grip (~95% of biacromial distance (BAD)) and has potential application for athletes performing explosive arm actions from positions where the hands are held close to the torso. Limited research has investigated CGBP mechanics compared to the TBP. Twenty-seven resistance-trained individuals completed a one-repetition maximum TBP and CGBP. The TBP was performed with the preferred grip; the CGBP with a grip width of 95% BAD. A linear position transducer measured lift distance and duration; peak and mean power, velocity, and force; distance and time when peak power occurred; and work. Pre-sticking region (PrSR), sticking region, and post-sticking region distance and duration for each lift was measured. A repeated measures ANOVA was used to derive differences between TBP and CGBP mechanics (p < 0.01); effect sizes (d) were also calculated. A greater load was lifted in the TBP, thus mean force was greater (d = 0.16–0.17). Peak power and velocity were higher in the CGBP, which had a longer PrSR distance (d = 0.49–1.32). The CGBP could emphasize power for athletes that initiate explosive upper-body actions with the hands positioned close to the torso.
      PubDate: 2017-06-24
      DOI: 10.3390/sports5030046
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 47: Exploring Motivation and Barriers to Physical
           Activity among Active and Inactive Australian Adults

    • Authors: Erin Hoare, Bill Stavreski, Garry Jennings, Bronwyn Kingwell
      First page: 47
      Abstract: Physical inactivity is a major global public health issue associated with a range of chronic disease outcomes. As such, the underlying motivation and barriers to whether or not an individual engages in physical activity is of critical public health importance. This study examines the National Heart Foundation of Australia Heart Week Survey conducted in March 2015. A total of 894 (40% female) Australian adults aged 25–54 years completed the survey, including items relating to motivation and barriers to being physically active. The most frequently selected responses regarding motivation for physical activity among those categorised as active (n = 696) were; to lose or maintain weight (36.6%, 95% CI 33.1–40.3), avoid or manage health condition (17.8%, 95% CI 15.1–20.8), and improve appearance (12.8%, 95% CI 10.5–15.5). Some gender differences were found with a greater proportion of females (43.8%, 95% CI 38.0–49.8) reporting lose or maintain weight as their main motivation for being physically active compared to males (31.9%, 95% CI 27.7–36.6). Among those categorised as inactive (n = 198), lack of time (50.0%, 95% CI 43.0–56.8) was the most frequently reported barrier to physical activity. While empirical studies seek to understand the correlates and determinants of physical activity, it is critical that beliefs and perceptions enabling and prohibiting engagement are identified in order to optimise physical activity promotion in the community.
      PubDate: 2017-06-28
      DOI: 10.3390/sports5030047
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 48: Development of a Digital-Based Instrument to
           Assess Perceived Motor Competence in Children: Face Validity, Test-Retest
           Reliability, and Internal Consistency

    • Authors: Leah Robinson, Kara Palmer
      First page: 48
      Abstract: Assessing children’s perceptions of their movement abilities (i.e., perceived competence) is traditionally done using picture scales—Pictorial Scale of Perceived Competence and Acceptance for Young Children or Pictorial Scale of Perceived Movement Skill Competence. Pictures fail to capture the temporal components of movement. To address this limitation, we created a digital-based instrument to assess perceived motor competence: the Digital Scale of Perceived Motor Competence. The purpose of this study was to determine the validity, reliability, and internal consistency of the Digital-based Scale of Perceived Motor Skill Competence. The Digital-based Scale of Perceived Motor Skill Competence is based on the twelve fundamental motor skills from the Test of Gross Motor Development-2nd Edition with a similar layout and item structure as the Pictorial Scale of Perceived Movement Skill Competence. Face Validity of the instrument was examined in Phase I (n = 56; Mage = 8.6 ± 0.7 years, 26 girls). Test-retest reliability and internal consistency were assessed in Phase II (n = 54, Mage = 8.7 years ± 0.5 years, 26 girls). Intra-class correlations (ICC) and Cronbach’s alpha were conducted to determine test-retest reliability and internal consistency for all twelve skills along with locomotor and object control subscales. The Digital Scale of Perceived Motor Competence demonstrates excellent test-retest reliability (ICC = 0.83, total; ICC = 0.77, locomotor; ICC = 0.79, object control) and acceptable/good internal consistency (α = 0.62, total; α = 0.57, locomotor; α = 0.49, object control). Findings provide evidence of the reliability of the three level digital-based instrument of perceived motor competence for older children.
      Citation: Sports
      PubDate: 2017-07-04
      DOI: 10.3390/sports5030048
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 49: Body Mass Index in the Early Years in Relation
           to Motor Coordination at the Age of 5–7 Years

    • Authors: Arto Laukkanen, Arto J. Pesola, Taija Finni, Arja Sääkslahti
      First page: 49
      Abstract: Physical activity (PA) and body mass index (BMI) are consistently associated with motor coordination (MC) in children. However, we know very little how BMI in early childhood associates with MC later in childhood. This study investigated associations between BMI in early childhood and BMI, PA, and MC in middle childhood. Children aged 5 to 7 years (n = 64, 32 girls) were measured for MC using Körperkoordinationstest für Kinder (KTK) and for moderate-to-vigorous PA (MVPA) using triaxial accelerometers. Prevailing body weight and height were measured, and information on weight and height in early years was based on parental report of child health care report cards. Age-adjusted BMIz scores were calculated on the basis of international growth curve references. Associations and the explained variability of MC were investigated by Pearson correlations and a hierarchical multiple regression analysis. Age and MVPA were found to be significantly associated with MC at middle childhood, in general. BMIz at middle childhood and at ages 4 and 5 years inversely explained 12% (p < 0.05), 6% (p > 0.05), and 7% (p > 0.05) of the variation in MC in girls after adjusting for covariates, respectively. In boys, BMIz scores did not show any trend of association with MC. This study suggests sex-specific mechanisms in the interplay between BMI and motor development in childhood.
      Citation: Sports
      PubDate: 2017-07-07
      DOI: 10.3390/sports5030049
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 50: Determinants and Reasons for Dropout in Swimming
           —Systematic Review

    • Authors: Diogo Monteiro, Luis Cid, Daniel Marinho, João Moutão, Anabela Vitorino, Teresa Bento
      First page: 50
      Abstract: The present research aims to systematically review the determinants and reasons for swimming dropout. The systematic review was conducted through electronic searches on the Web of Knowledge and PsycInfo databases from 2 February to 29 July 2015, using the keywords dropout, withdrawal, motives, reasons, sport, framework-theories, motivation, swim*, review, attrition and compliance. Fifteen studies were found and six were fully reviewed and its data extracted and analysed. Most studies were undertaken in Canada and in the United States of America (USA), and one study was conducted in Spain. Most participants were female (65.74%), and the main reasons for dropout were ‘conflicts with their trainers’, ‘other things to do’, ‘competence improvements’ failure’, ‘parents, couples or trainers’ pressure’, ‘lack of enjoyment’ and ‘get bored’. This review contributes to the present knowledge on the understanding of dropout in swimming. However, it is necessary to continue researching on this topic, validating measurement instruments and studying the motivational processes related to dropout and persistence.
      Citation: Sports
      PubDate: 2017-07-10
      DOI: 10.3390/sports5030050
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 51: Increases in Variation of Barbell Kinematics Are
           Observed with Increasing Intensity in a Graded Back Squat Test

    • Authors: Kevin Carroll, Kimitake Sato, Caleb Bazyler, N. Triplett, Michael Stone
      First page: 51
      Abstract: The purpose of the current study was two-fold: (1) To examine the variation in velocity and power with increasing intensity in the back squat among subjects; and (2) To explore individual subject characteristics as possible explanations for variations of velocity in the back squat. Fourteen recreationally trained male subjects with experience in the back squat agreed to participate in the study (age = 25.0 ± 2.6 years, height = 178.9 ± 8.1 cm, body mass = 88.2 ± 15.8 kg). One-repetition maximums (1RM) were performed for each subject on force platforms with four linear position transducers attached to the barbell. The 1RM assessment was immediately preceded by warm-up sets at 65%, 75%, 85%, and 95% of estimated 1RM for 5, 3, 2, and 1 repetitions, respectively. Mean concentric velocity (MCV) and mean power were recorded for each intensity condition and were analyzed using Pearson correlation to determine the relationship between each variable and relative intensity (%1RM). Statistically significant negative relationships existed between %1RM and MCV (r = −0.892) and mean power (r = −0.604). Between-subject coefficient of variation tended to increase as %1RM increased for both MCV and mean power. These results suggest that MCV is superior to mean power as an indicator of relative intensity in the back squat. Additionally, the between-subject variation observed at higher intensities for MCV and mean power support the use of velocity ranges by strength and conditioning coaches.
      Citation: Sports
      PubDate: 2017-07-14
      DOI: 10.3390/sports5030051
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 52: Effect of Yang-Style Tai Chi on Gait Parameters
           and Musculoskeletal Flexibility in Healthy Chinese Older Women

    • Authors: Liye Zou, Chaoyi Wang, Zuguo Tian, Huiru Wang, Yankai Shu
      First page: 52
      Abstract: The purpose of the present study was to examine the effect of Yang-style Tai chi (TC) on gait parameters and musculoskeletal flexibility in healthy Chinese female adults. Sixty-six female adults aged >65 years were randomly assigned to either an experimental group (67.9 ± 3.2 years of age) receiving three 90-min simplified 24-form TC sessions for eight weeks, or a control group (67.4 ± 2.9 years of age) who maintained their daily lifestyles. All study participants were instructed to perform a selected pace walking for recording gait parameters (stride length, gait speed, swing cycle time, stance phase, and double support times) at both baseline and after the experiment. Low-limb flexibility and range of motion at specific musculoskeletal regions (hip flexion, hip extension, and plantar flexion, as well as anterior and lateral pelvic tilts, pelvic rotation, and joint range of motion (hip, knee, and ankle)) were also assessed in the present study. Multiple separate 2 × 2 Factorial Analysis of Variance (ANOVA) with repeated measures were used to examine the effects of TC on the abovementioned outcomes between baseline and posttest in the two groups. When compared to those in the control group, older female adults who experienced the 8-week Tai chi intervention demonstrated significant improvements in most of the outcome measures. More specifically, positive changes in the TC group were found, including gait parameter (p < 0.001 for all; stride length (1.12 to 1.24, +8.6%), gait speed (1.06 to 1.21, +13.9%), stance phase (66.3 to 61.8, −5.5%), swing phase (33.7 to 38.4, +10.1%), double support time (0.33 to 0.26, −21.1%)), flexibility-related outcomes (hip flexion (90.0 to 91.9, 22.6%, p < 0.0001), single hip flexor (6.0 to 2.0, −61.5%, p = 0.0386), and plantar flexion (41.6 to 49.7, +17.5%, p < 0.0001)), and range of motion (anterior pelvic tilt (9.5 to 6.2, −34.7%, p < 0.0001), lateral pelvic tilt (6.6 to 8.3, +23.8%, p = 0.0102), pelvic rotation (10.3 to 14.7, 28.2%, p < 0.0001), hip range of motion (29.8 to 32.9, +13.5%, p = 0.001), and ankle range of motion (28.0 to 32.6, +11.1%, p < 0.0001)). The present study supports the notion that the practice of TC has a positive effect on healthy older female adults in improving gait parameters and flexibility, counteracting the normal functional degeneration due to age.
      Citation: Sports
      PubDate: 2017-07-17
      DOI: 10.3390/sports5030052
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 53: Exploring the Utilisation of Stand up Paddle
           Boarding in Australia

    • Authors: Ben Schram, James Furness
      First page: 53
      Abstract: Stand Up Paddle Boarding (SUP) has grown exponentially in the last few years with unprecedented participation rates globally. Despite some scientific research on physiological and performance variables, minimal information exists regarding participation and utilisation. The purpose of this study was to discover more about how and where people participate in the relatively new sport of SUP. An open-source online survey application was administered internationally to active SUP participants to capture information relevant to both demographics and participation. Of a total of 240 responses, 154 (64.2%) were Australian. The average SUP rider was 42.9 ± 11.7 years, mass 80.4 ± 18.7 kg, 1.75 ± 0.10 m tall with a BMI of 26.1 ± 4.9. More males (69.5%) participate in SUP than females with the majority of participants from the eastern seaboard of Australia. Participants most commonly used SUP for fun and fitness, for around 3 h per week, predominantly at the beach with friends, with around half of the respondents reporting a competitive involvement. This is the first study to date to quantify participation of SUP within Australia. Results revealed SUP is a global activity with a high representation within Australia. Key findings from this study reveal the geographical and demographic distribution of SUP use. Consequently, these findings may inform the industry about its target audience. Additionally, information regarding the ‘typical’ SUP rider may serve to further promote and grow the sport.
      Citation: Sports
      PubDate: 2017-07-22
      DOI: 10.3390/sports5030053
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 54: Athlete Self-Report Measure Use and Associated
           Psychological Alterations

    • Authors: Anna Saw, Luana Main, Sam Robertson, Paul Gastin
      First page: 54
      Abstract: The experience of athletes and practitioners has led to the suggestion that use of an athlete self-report measure (ASRM) may increase an athlete’s self-awareness, satisfaction, motivation, and confidence. This study sought to provide empirical evidence for this assertion by evaluating psychological alterations associated with ASRM use across a diverse athlete population. Athletes (n = 335) had access to an ASRM for 16 weeks and completed an online survey at baseline, and weeks 4, 8, and 16. Generalized estimating equations were used to evaluate the associations between ASRM compliance and outcome measures. Compared to baseline, confidence and extrinsic motivation were most likely increased at weeks 4, 8, and 16. Satisfaction and intrinsic motivation were most likely decreased at week 4, but no different to baseline values at weeks 8 and 16. Novice athletes and those who were instructed to use an ASRM (rather than using one autonomously) were less responsive to ASRM use. This study provides preliminary evidence for ASRM to prompt initial dissatisfaction and decreased intrinsic motivation which, along with increased confidence and extrinsic motivation, may provide the necessary stimulus to improve performance-related behaviors. Novice and less autonomous athletes may benefit from support to develop motivation, knowledge, and skills to use the information gleaned from an ASRM effectively.
      Citation: Sports
      PubDate: 2017-07-26
      DOI: 10.3390/sports5030054
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 55: Acute and Chronic Effects of Isometric Handgrip
           Exercise on Cardiovascular Variables in Hypertensive Patients: A
           Systematic Review

    • Authors: Breno Farah, Antônio Germano-Soares, Sergio Rodrigues, Camila Santos, Sávio Barbosa, Lauro Vianna, Véronique Cornelissen, Raphael Ritti-Dias
      First page: 55
      Abstract: The aim of this study was to describe, through a systematic review, the acute and chronic effects of isometric handgrip exercise on cardiovascular variables in hypertensive individuals. In this systematic review, we included studies that analyzed whether a single bout or a program with isometric exercises affect cardiovascular variables in hypertensive adults. The electronic database PubMed/Medline was searched for relevant studies published until May 2017. Of the 2927 studies initially identified, 2916 were excluded based on title and abstract and five on the basis of full-text assessment, leaving six studies remaining. In addition, one further study cited in the references of the included articles was included in this review, totaling seven studies included (five studies on the chronic effects of isometric handgrip exercise on cardiovascular parameters). None of the acute studies observed post-exercise hypotension. The majority of the chronic studies found decreases in office blood pressure after isometric handgrip training, with training ranging from 6 to 10 weeks, while heart rate variability parameters were improved in one study and did not change in another. Reduction in oxidative stress was observed; however, this variable was only analyzed in one study. In hypertensives, acute responses to isometric handgrip exercise are very limited due to the small number of studies, therefore more research is required. Furthermore, chronic isometric handgrip training reduces blood pressure; however, there is still a gap in the knowledge on the effects of this modality of exercise on other cardiovascular variables—such as endothelial function, oxidative stress, and cardiac autonomic modulation—which should be addressed in future studies.
      Citation: Sports
      PubDate: 2017-08-01
      DOI: 10.3390/sports5030055
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 56: The Relationship between Sport Participation and
           Chronic Diseases among Men in the USA: An Examination of the Behavioral
           Risk Factor Surveillance System

    • Authors: Jennifer Pharr, Nancy Lough
      First page: 56
      Abstract: Sport participation has been associated with lower rates of chronic diseases when compared to other forms of physical activity (PA) among women. However, we do not know if this relationship holds true for men. The purpose of this study was to examine the relationship between sport participation and men’s health and chronic diseases in the USA. This study was a secondary data analysis of the 2015 national Behavioral Risk Factor Surveillance System (BRFSS) survey. Participants were questioned extensively about their PA behaviors. Seventy-six different activities were identified and these activities were categorized as sport, conditioning exercise, recreation, or household tasks based upon previously identified categories. Logistic regression was utilized to calculate odds and adjusted odds ratios for chronic diseases based on physical activity category. When compared to men who participated in sport, men in the other PA categories had significantly higher odds for all of the chronic diseases except asthma. After controlling for demographic variables, significant odds remain except for stroke. Higher odds for chronic diseases in the other PA categories indicates that men in these group have a higher risk for chronic diseases than men in the sport category. Because of the potential health improvements related to sports participation, it is important to maintain and increase sport participation for both adolescents and adults.
      Citation: Sports
      PubDate: 2017-08-02
      DOI: 10.3390/sports5030056
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 57: Effects of Heart Rate vs. Speed-Based High
           Intensity Interval Training on Aerobic and Anaerobic Capacity of Female
           Soccer Players

    • Authors: Hamid Arazi, Abbas Keihaniyan, Amin EatemadyBoroujeni, Amir Oftade, Sheida Takhsha, Abbas Asadi, Rodrigo Ramirez-Campillo
      First page: 57
      Abstract: The purpose of this study was to compare the effects of two types of high-intensity interval training (HIIT) programs on aerobic and anaerobic capacity of female soccer players. Regional-level female athletes were randomly divided into heart rate-based HIIT (n = 8; age 23.4 ± 1.1 year) and speed-based HIIT groups (n = 8; age 23.4 ± 1.3 year). Athletes trained three days per week for six weeks. Before and after training, each athlete’s performance was assessed directly through the Hoff test, 30-15 Intermittent Fitness Test (VIFT), and repeated-sprint ability test (RAST); maximal oxygen consumption (VO2max), power and fatigue were estimated indirectly. Both experimental groups improved power, fatigue index and VO2max after training (p < 0.05). It was noteworthy that the speed-based group had greater gains in minimal power (effect size (ES): 3.99 vs. 0.75), average power (ES: 2.23 vs. 0.33), and fatigue index (ES: 2.53 vs. 0.17) compared to heart rate-based group (p < 0.05). In conclusion, both heart rate-based and speed-based HIIT induced meaningful improvements in power, VO2max, and fatigue index in female soccer players, although the speed-based HIIT group achieved greater gains in power and fatigue index compared to the heart rate-based group.
      Citation: Sports
      PubDate: 2017-08-04
      DOI: 10.3390/sports5030057
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 58: Are We Compensating for the Lack of Physical
           Activity in Our Diabetic Patients with Treatment Intensification'

    • Authors: Maja Maja Cigrovski Berkovic, Ines Bilic-Curcic, Marina Gradiser, Davorka Herman-Mahecic, Vjekoslav Cigrovski, Marul Ivandic
      First page: 58
      Abstract: Background: We studied the association between leisure time physical activity (LTPA) and glycemic control, body mass index (BMI), and hypoglycemic incidents in type 1 (T1DM) and type 2 diabetes patients (T2DM). Methods: This is a cross-sectional study of 198 diabetic patients (60 with type 1 diabetes, 138 with type 2 diabetes). LTPA was assessed by a validated 12-month questionnaire. Patients were grouped as sedentary and moderately to vigorously active. Outcome measures were Hemoglobin A1c (HbA1c), BMI, and hypoglycemic episodes. Results: LTPA effect on the HbA1c reduction was present in diabetes type 1 patients. Patients who were involved in the moderate to vigorous-intensity physical activity had a greater decrease in the HbA1c (p = 0.048) than patients with low physical activity (p = 0.085). Level of LTPA was neither associated with increased number of hypoglycemic episodes, nor BMI. After an average of 4 years of diabetes, the number of patients requiring more than one antidiabetic agent increased, although the observed difference did not correlate with LTPA level. Conclusions: LTPA has an influence on the regulation of diabetes type 1, and intensification of medical treatment is compensating for the lack of lifestyle change—especially in type 2 diabetics.
      Citation: Sports
      PubDate: 2017-08-07
      DOI: 10.3390/sports5030058
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 59: Longitudinal Change in the Relationship between
           Fundamental Motor Skills and Perceived Competence: Kindergarten to Grade 2

    • Authors: Jeff Crane, John Foley, Patti-Jean Naylor, Viviene Temple
      First page: 59
      Abstract: As children transition from early to middle childhood, the relationship between motor skill proficiency and perceptions of physical competence should strengthen as skills improve and inflated early childhood perceptions decrease. This study examined change in motor skills and perceptions of physical competence and the relationship between those variables from kindergarten to grade 2. Participants were 250 boys and girls (Mean age = 5 years 8 months in kindergarten). Motor skills were assessed using the Test of Gross Motor Development-2 and perceptions were assessed using a pictorial scale of perceived competence. Mixed-design analyses of variance revealed there was a significant increase in object-control skills and perceptions from kindergarten to grade 2, but no change in locomotor skills. In kindergarten, linear regression showed that locomotor skills and object-control skills explained 10% and 9% of the variance, respectively, in perceived competence for girls, and 7% and 11%, respectively, for boys. In grade 2, locomotor skills predicted 11% and object-control skills predicted 19% of the variance in perceptions of physical competence, but only among the boys. Furthermore, the relationship between motor skills and perceptions of physical competence strengthened for boys only from early to middle childhood. However, it seems that forces other than motor skill proficiency influenced girls’ perceptions of their abilities in grade 2.
      Citation: Sports
      PubDate: 2017-08-10
      DOI: 10.3390/sports5030059
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 60: Do Image-Assisted Mobile Applications Improve
           Dietary Habits, Knowledge, and Behaviours in Elite Athletes' A Pilot

    • Authors: Anne Simpson, Luke Gemming, Dane Baker, Andrea Braakhuis
      First page: 60
      Abstract: To date, there has been a paucity of research on optimal ways to educate and promote dietary behavioural change within athletes. Optimising athlete nutrition is fundamental to reaching peak performance and maintaining athlete wellbeing. MealLogger® is a smartphone application that incorporates the use of an image-based food record and social-media functionality to provide in-application personalised feedback to individuals or groups, peer-support, and a platform to deliver nutrition education material. This study measured the feasibility of MealLogger® within New Zealand elite male field hockey players (n = 17) aged 18–20 to increase athlete knowledge and nutrition promoting behaviours. During a six-week intervention, participants were instructed to log images of their meals three days per week and they received individualised dietetic feedback on logged meals. Weekly nutrition-education fact-sheets and videos were delivered through the application. Nutrition knowledge increased moderately from baseline (%Pre 54.7 ± 14.3; %Post 61.1 ± 11.45, p = 0.01). Participants report a highly positive experience of application use (8/10) with 82.3% attempting to make positive changes in dietary behaviours based on in-app education. All participants preferred this method to traditional methods of dietary analysis. Using image-based applications such as MealLogger® is an effective approach to monitor dietary intake and deliver education to optimise the nutritional behaviours of elite athletes.
      Citation: Sports
      PubDate: 2017-08-11
      DOI: 10.3390/sports5030060
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 61: Efficacy of Carbohydrate Ingestion on CrossFit
           Exercise Performance

    • Authors: Jaden Rountree, Ben Krings, Timothy Peterson, Adam Thigpen, Matthew McAllister, Megan Holmes, JohnEric Smith
      First page: 61
      Abstract: The efficacy of carbohydrate (CHO) ingestion during high-intensity strength and conditioning type exercise has yield mixed results. However, little is known about shorter duration high-intensity exercise such as CrossFit. The purpose of this study was to investigate the performance impact of CHO ingestion during high-intensity exercise sessions lasting approximately 30 min. Eight healthy males participated in a total of four trials; two familiarizations, a CHO trial, and a similarly flavored, non-caloric placebo (PLA) trial. CrossFit’s “Fight Gone Bad Five” (FGBF) workout of the day was the exercise model which incorporated five rounds of maximal repetition exercises, wall throw, box jump, sumo deadlift high pull, push press, and rowing, followed by one minute of rest. Total repetitions and calories expended were summated from each round to quantify total work (FGBF score). No difference was found for the total work between CHO (321 ± 51) or PLA (314 ± 52) trials (p = 0.38). There were also no main effects (p > 0.05) for treatment comparing exercise performance across rounds. Based on the findings of this study, it does not appear that ingestion of CHO during short duration, high-intensity CrossFit exercise will provide a beneficial performance effect.
      Citation: Sports
      PubDate: 2017-08-14
      DOI: 10.3390/sports5030061
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 62: Health Care as a Team Sport'—Studying
           Athletics to Improve Interprofessional Collaboration

    • Authors: Anthony P. Breitbach, Scott Reeves, Simon N. Fletcher
      First page: 62
      Abstract: Organizations value teamwork and collaboration as they strive to build culture and attain their goals and objectives. Sports provide a useful and easily accessible means to study teamwork. Interprofessional collaborative practice (IPCP) has been identified as a means of improving patient and population health outcomes. Principles of teamwork in sports can inform health professionals and organizations regarding possible improvement strategies and barriers in the optimization of IPCP. Twenty-eight delegates from the 2017 All Together Better Health Conference in Oxford, UK participated in a World Café to discuss the how teamwork in sports can inform IPCP in healthcare and sports medicine. These discussions were captured, transcribed and coded using the domains developed by the Interprofessional Education Collaborative (IPEC) along with extrapersonal or interpersonal loci. Extrapersonal factors regarding structure of leadership, roles and organizational commitment can be positive factors to promote teamwork. However, interpersonal factors affecting communication, values and lack of commitment to collaboration can serve as barriers. Athletic trainers and other sports medicine professionals can serve as valuable members of interprofessional teams and teamwork is essential in the field of sports medicine.
      Citation: Sports
      PubDate: 2017-08-18
      DOI: 10.3390/sports5030062
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 63: Differences in Vertical Jump Force-Time

    • Authors: Christopher Thomas, Irene Kyriakidou, Thomas Dos’Santos, Paul Jones
      First page: 63
      Abstract: The countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) are commonly used to compare one’s force capacity during dynamic and isometric assessments, respectively. However, little research has investigated the influence of maximum isometric strength on drop-jump (DJ) performance. Therefore, the purpose of this study was to explore differences in CMJ and DJ force-time characteristics between stronger and weaker adolescent male basketball players. Sixteen adolescent male basketball players performed the IMTP to assess measures of peak force (IMTP PF), whereas CMJ and DJ calculated a range of kinetic and kinematic variables. Peak concentric force (CMJ-PF) in the CMJ was greater for stronger players (d = 1.99). However, no differences in DJ force-time characteristics existed between stronger and weaker players. Future research should be undertaken to investigate the role of maximum strength on DJ force-time characteristics in adolescent male basketball players. Such studies may help direct the creation of athlete training and monitoring programs more effectively to represent accurate player profiling.
      Citation: Sports
      PubDate: 2017-08-24
      DOI: 10.3390/sports5030063
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 64: The Effects of a 4-Week, Intensified Training,
           and Competition Period on Salivary Hormones, Immunoglobulin A, Illness
           Symptoms, and Mood State in Elite Synchronised Swimmers

    • Authors: Amy Tanner, Shannon Day
      First page: 64
      Abstract: Given the limited research into the physiological and psychological demands of elite synchronised swimming, the aim of this study was to examine 10 elite female synchronised swimmers and analyse the relationship between training load, stress, illness episodes, and salivary biomarkers during a period of training and competition. Saliva samples were collected before (BASE), during an intensified training camp (CAMP), during an international competition period (COMP), and post competition recovery (REC) for analysis of cortisol, testosterone, and secretory immunoglobulin A (SIgA). Illness symptoms, Daily Analysis of Life Demands of Athletes (DALDA), and training load were also monitored. Training load significantly increased from BASE during CAMP and COMP (p < 0.01), and SIgA secretion was higher during COMP compared to BASE and CAMP (p < 0.01). There was no change in salivary testosterone; however, salivary cortisol was elevated during COMP compared to BASE (93%, p < 0.05). DALDA ‘a scores’ were correlated with salivary cortisol (r = 0.429, p = 0.0001). The study demonstrates that a short period of intensified training and competition did not have a detrimental effect on mucosal immunity in elite synchronised swimmers; however, swimmers displayed higher cortisol levels during the competition and increased stress symptoms.
      Citation: Sports
      PubDate: 2017-09-01
      DOI: 10.3390/sports5030064
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 65: Between-Leg Mechanical Differences as Measured
           by the Bulgarian Split-Squat: Exploring Asymmetries and Relationships with
           Sprint Acceleration

    • Authors: Robert Lockie, Fabrice Risso, Adrina Lazar, Dominic Giuliano, Alyssa Stage, Tricia Liu, Megan Beiley, Jillian Hurley, Ibett Torne, John Stokes, Samantha Birmingham-Babauta, DeShaun Davis, Ashley Orjalo, Matthew Moreno
      First page: 65
      Abstract: Between-leg strength differences can negatively influence sprint acceleration. The challenge is to find a method to measure this within a unilateral exercise. This study analyzed a five repetition-maximum (5RM) Bulgarian split-squat (BSS) to identify between-leg differences for the dominant and non-dominant legs in peak and mean power, force, and velocity as measured by a linear position transducer. Between-leg differences in these variables were correlated with 20-m (0–5, 0–10, 0–20 m intervals) sprint velocity. Eight men were assessed in the 5RM BSS and 20-m sprint. T-tests calculated between-leg differences in power, force, and velocity. Spearman’s correlations calculated relationships between the between-leg differences in the mechanical variables with velocity over each interval. When comparing the dominant and non-dominant legs, there were significant (p = 0.002–0.056) differences in 11 of 12 variables. However, percentage differences were low (~0.3–12%). There was one large, non-significant correlation (best repetition mean force between-leg difference and 0–5 m velocity; ρ = −0.810) out of 36 relationships. The BSS can provide a profile of between-leg differences in power, force, and velocity. There were limited relationships between the BSS between-leg differences and 20-m sprint velocities. Smaller between-leg differences in BSS power, force, and velocity could ensure minimal impact on acceleration.
      Citation: Sports
      PubDate: 2017-09-01
      DOI: 10.3390/sports5030065
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 66: The Relationships between Hip and Knee Extensor
           Cross-Sectional Area, Strength, Power, and Potentiation Characteristics

    • Authors: Timothy Suchomel, Michael Stone
      First page: 66
      Abstract: The purpose of this study was to examine the relationships between muscle cross-sectional area (CSA), maximal strength, power output, and maximum potentiation characteristics. The vastus lateralis and biceps femoris CSA, one repetition maximum (1RM) back squat, 1RM concentric-only half-squat (COHS) strength, static jump power output, and maximum potentiation characteristics of 17 resistance-trained men was assessed during several testing sessions. Pearson’s correlation coefficients were used to examine the relationships between CSA, strength, power output, and maximum potentiation measures. Moderate-to-strong relationships existed between CSA and strength measures (r = 0.462–0.643) as well as power output (r = 0.396–0.683). In addition, moderate-to-strong relationships existed between strength and power output (r = 0.407–0.548), while trivial relationships existed between strength and maximum potentiation (r = −0.013–0.149). Finally, small negative relationships existed between CSA and maximum potentiation measures (r = −0.229–−0.239). The results of the current study provide evidence of the interplay between muscle CSA, strength, power, and potentiation. Vastus lateralis and biceps femoris CSA may positively influence an individual’s back squat and COHS maximal strength and squat jump peak power; however, muscle CSA and absolute strength measures may not contribute to an individual’s potentiation capacity. Practitioners may consider implementing resistance training strategies that improve vastus lateralis and biceps femoris size in order to benefit back squat and COHS strength. Furthermore, implementing squatting variations—both full and partial—may benefit jumping performance.
      Citation: Sports
      PubDate: 2017-09-05
      DOI: 10.3390/sports5030066
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 67: The Utility of the Supine-to-Stand Test as a
           Measure of Functional Motor Competence in Children Aged 5–9 Years

    • Authors: Michael Duncan, Chelsey Lawson, Leanne Walker, David Stodden, Emma Eyre
      First page: 67
      Abstract: This study examined how supine-to-stand (STS) performance is related to process and product assessment of motor competence (MC) in children. Ninety-one children aged 5–9 years were assessed for process and product MC (10 m running speed and standing long jump) as well as process and product measures of STS. Tertiles were created for STS process and STS product scores to create 3 groups reflecting low, medium, and high STS competency. ANCOVA analysis, controlling for age, for process STS, indicated that process MC was significantly higher in children, classified as medium STS (p = 0.048) and high STS (p = 0.011) competence, and that 10 m run speed was slower for low STS compared to medium (p = 0.019) and high STS (p = 0.004). For product STS tertiles, process MC was significantly higher for children in the lowest (fastest) STS tertile compared to those in the medium highest (slowest) tertile (p = 0.01).
      Citation: Sports
      PubDate: 2017-09-12
      DOI: 10.3390/sports5030067
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 68: Relationships between Isometric Force-Time
           Characteristics and Dynamic Performance

    • Authors: Thomas Dos’Santos, Christopher Thomas, Paul Comfort, John McMahon, Paul Jones
      First page: 68
      Abstract: The purpose of this study was to explore the relationships between isometric mid-thigh pull (IMTP) force-time characteristics (peak force and time-specific force vales (100–250 ms)) and dynamic performance and compare dynamic performance between stronger and weaker athletes. Forty-three athletes from different sports (rowing, soccer, bicycle motocross, and hockey) performed three trials of the squat jump (SJ), countermovement jump (CMJ), and IMTP, and performed a one repetition maximum power clean (PC). Reactive strength index modified (RSImod) was also calculated from the CMJ. Statistically significant large correlations between IMTP force-time characteristics and PC (ρ = 0.569–0.674, p < 0.001), and moderate correlations between IMTP force-time characteristics (excluding force at 100 ms) and RSImod (ρ = 0.389–0.449, p = 0.013–0.050) were observed. Only force at 250 ms demonstrated a statistically significant moderate correlation with CMJ height (ρ = 0.346, p = 0.016) and no statistically significant associations were observed between IMTP force-time characteristics and SJ height. Stronger athletes (top 10) demonstrated statistically significantly greater CMJ heights, RSImods, and PCs (p ≤ 0.004, g = 1.32–1.89) compared to weaker (bottom 10) athletes, but no differences in SJ height were observed (p = 0.871, g = 0.06). These findings highlight that the ability to apply rapidly high levels of force in short time intervals is integral for PC, CMJ height, and reactive strength.
      Citation: Sports
      PubDate: 2017-09-13
      DOI: 10.3390/sports5030068
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 69: Effect of New Zealand Blackcurrant Extract on
           Performance during the Running Based Anaerobic Sprint Test in Trained
           Youth and Recreationally Active Male Football Players

    • Authors: Charlie Godwin, Matthew Cook, Mark Willems
      First page: 69
      Abstract: It was observed previously that New Zealand blackcurrant (NZBC) extract reduced slowing of the maximal 15 m sprint speed during the Loughborough Intermittent Shuttle Test. We examined the effect of NZBC extract on the performance of the Running Based Anaerobic Sprint Test (RAST, 6 × 35-m sprints with 10 seconds passive recovery) in trained youth and recreationally active football players. Fifteen recreationally active (University team) (age: 20 ± 1 years, height: 174 ± 19 cm, body mass: 80 ± 13 kg) and nine trained youth players (English professional club) (age: 17 ± 0 years, height: 178 ± 8 cm, body mass: 69 ± 9 kg, mean ± SD) participated in three testing sessions. Prior to the RASTs, participants consumed two capsules of NZBC extract (600 mg∙day−1 CurraNZ®) or placebo (P) for 7 days (double blind, randomised, cross-over design, wash-out at least 14 days). Ability difference between groups was shown by sprint 1 time. In the placebo condition, trained youth players had faster times for sprint 1 (5.00 ± 0.05 s) than recreationally active players (5.42 ± 0.08 s) (p < 0.01). In trained youth players, there was a trend for an effect of NZBC extract (p = 0.10) on the slowing of the sprint 1 time. NZBC extract reduced slowing of the sprint 5 time (P: 0.56 ± 0.22 s; NZBC: 0.35 ± 0.25, p = 0.02) and this was not observed in recreationally active players (P: 0.57 ± 0.48 s; NZBC: 0.56 ± 0.33, p = 0.90). For fatigue index, expressed as a % change in fastest sprint time, there was a strong trend to be lower in both trained youth and recreationally active players combined by NZBC extract (P: −13 ± 7%; NZBC: −11 ± 6%, p = 0.06) with 12 participants (five trained youth) experiencing less fatigue. New Zealand blackcurrant extract seems to benefit repeated sprint performance only in trained football players.
      Citation: Sports
      PubDate: 2017-09-15
      DOI: 10.3390/sports5030069
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 70: Comparison of Different Minimal Velocity
           Thresholds to Establish Deadlift One Repetition Maximum

    • Authors: Jason Lake, David Naworynsky, Freddie Duncan, Matt Jackson
      First page: 70
      Abstract: The aim of this study was to compare the actual deadlift one repetition maximum (1RM) and the deadlift 1RM predicted from individualised load-velocity profiles. Twelve moderately resistance-trained men participated in three deadlift sessions. During the first, 1RM was assessed; during the second, load-velocity profiles were recorded with six loads (65% to 90% 1RM) using a linear position transducer recording at 1000 Hz; and during the third, minimal velocity thresholds (MVT) were recorded from the velocity of the last repetition during sets to volitional fatigue with 70% and 80% 1RM with a linear position transducer recording at 1000 Hz. Regression was then used to generate individualised load-velocity profiles and the MVT was used as a cut-off value from which to predict deadlift 1RM. In general, velocity reliability was poor to moderate. More importantly, predicted deadlift 1RMs were significantly and meaningfully less than actual deadlift 1RMs (p < 0.05, d = 1.03–1.75). The main practical application that should be taken from the results of this study is that individualized load-velocity profiles should not be used to predict deadlift 1RM. Practitioners should not use this method in combination with the application of MVT obtained from the last repetition of sets to volitional fatigue.
      Citation: Sports
      PubDate: 2017-09-19
      DOI: 10.3390/sports5030070
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 71: A Comparison of Dynamic Strength Index between
           Team-Sport Athletes

    • Authors: Christopher Thomas, Thomas Dos’Santos, Paul Jones
      First page: 71
      Abstract: The purpose of this study was to examine the differences in countermovement jump peak force (CMJ-PF), isometric mid-thigh pull peak force (IMTP-PF), and resultant dynamic strength index (DSI) values between team-sport athletes. One hundred and fifteen male and female team-sport athletes performed the CMJ and IMTP to determine peak force (CMJ-PF and IMTP-PF, respectively). Statistically and practically significant differences (p ≤ 0.050; d = 0.49–1.32) in CMJ-PF were evident between teams. Specifically, the greatest CMJ-PFs were produced by the male cricket players and were followed in order by the male basketball, male soccer, female netball, female cricket, and female soccer players. Statistically and practically significant differences (p ≤ 0.045; d = 0.64–1.78) in IMTP-PF existed among sports teams, with the greatest IMTP-PFs were produced by the male soccer players and were followed in order by the male cricket, male basketball, female netball, female soccer, and female cricket players. Statistically and practically significant differences (p ≤ 0.050; d = 0.92–1.44) in DSI were found between teams. These findings demonstrate that CMJ-PF, IMTP-PF, and DSI differ between sports teams and provide normative data for ballistic and isometric PF measures. Strength and conditioning coaches should consider relative changes in CMJ-PF and IMTP-PF when assessing DSI ratios.
      Citation: Sports
      PubDate: 2017-09-20
      DOI: 10.3390/sports5030071
      Issue No: Vol. 5, No. 3 (2017)
  • Sports, Vol. 5, Pages 21: Sports Nutrition Knowledge, Perceptions,
           Resources, and Advice Given by Certified CrossFit Trainers

    • Authors: Cassie Maxwell, Kyle Ruth, Carol Friesen
      First page: 21
      Abstract: Background: CrossFit is a large, growing force in the fitness community. Currently, Level 1 and 2 CrossFit certification classes do not include nutrition education. The purpose of this study was to identify sports nutrition knowledge, perceptions, resources, and advice given by Certified CrossFit Trainers. Methods: An online questionnaire that measured these four constructs was placed on a private Facebook community, open only to certified CrossFit trainers, for 10 days. Results: Complete surveys were obtained from 289 CrossFit trainers. The mean Sport Nutrition Knowledge (SNK) score was 11.1 ± 2.1, equivalent to 65.3% ± 12.4% correct. The trainers perceived nutrition to be extremely important to athletic performance (9.4 ± 0.9 on a 10 point scale). Overall, the trainers graded their SNK higher than that of their CrossFit peers. The internet and CrossFit peers were the most frequently reported sources for nutrition information; Registered Dietitians were the least reported source. The Paleo and Zone diets were the most common dietary regimens recommended by CrossFit trainers. Results indicated a positive correlation between a CrossFit trainer’s self-reported hours of nutrition education and their SNK score (r = 0.17; p < 0.01). Conclusion: Nutrition education modules for Level 1 and 2 CrossFit trainers, developed with input from Board Certified Specialists in Sports Dietetics, are recommended.
      PubDate: 2017-03-24
      DOI: 10.3390/sports5020021
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 22: Self-Concept in Adolescents—Relationship
           between Sport Participation, Motor Performance and Personality Traits

    • Authors: Markus Klein, Michael Fröhlich, Eike Emrich
      First page: 22
      Abstract: The relationship between sport participation, personality development, self-concept and self-esteem has been discussed repeatedly. In this research, a standardized written survey together with tests on motor performance were carried out with 1399 students (707 male; 692 female) in school years 7 (12.9 ± 0.6 years) and 10 (15.8 ± 0.6 years) to measure the extent of a relationship between physical self-concept (self-developed short scale) and sporting activity, measured motor performance (German motor performance test DMT (Deutscher Motorik-Test) 6–18) and report mark in physical education. Relationships were also analyzed between physical self-concept and general personality traits (neuroticism, extraversion, openness to experiences, compatibility, and conscientiousness, measured with NEO Five Factor Inventory (NEO-FFI)). The assessment of own physical attractiveness and own athleticism differs by sex (F(1, 962) = 35.21; p < 0.001), whereby girls assess themselves more critically. Weak significant relationships are displayed between motor performance and the assessment of own physical attractiveness (r(395) = 0.31; p < 0.01). Motor performance is given a higher predictive value with regard to a subject’s own self-concept, (physical attractiveness β = 0.37; t(249) = 5.24; p < 0.001; athleticism β = 0.40; t(248) = 6.81; p < 0.001) than the mark achieved in physical education (physical attractiveness β = −0.01; n.s.; athleticism β = −0.30; t(248) = 5.10; p < 0.001). Relationships were found overall between personality traits and physical self-concept. The influence of the ‘neuroticism’ trait is particularly strong (physical attractiveness β = −0.44; t(947) = −13.58; p < 0.001; athleticism β = −0.27; t(948) = −7.84; p < 0.001). The more pronounced this trait, the lower the assessment of own physical attractiveness and own athleticism.
      PubDate: 2017-04-04
      DOI: 10.3390/sports5020022
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 23: Lack of Reality: Positive Self-Perceptions of
           Health in the Presence of Disease

    • Authors: Vincent Dalbo, Masaru Teramoto, Michael Roberts, Aaron Scanlan
      First page: 23
      Abstract: The aim of this study was to determine if adults in Central Queensland have accurate self-perceptions of health. Data were collected as part of the 2010 Central Queensland Social Survey (N = 1289). Overweight/obesity is considered a health disorder and was determined using body mass index. Disease states were determined by asking respondents if they have: heart disease, high/low blood pressure, high cholesterol, high triglycerides, thyroid disorder, diabetes, and osteopenia/osteoporosis. Self-perceptions of health were assessed by asking, “Would you say that in general your health is” poor, fair, good, very good, excellent, don’t know, and no response. An accurate health perception occurred if: (1) A respondent with a disease/health disorder reported that their health was poor/fair or (2) A respondent without a disease/health disorder reported that their health was good/very good/excellent. The proportions of people with an accurate health perception by disease/health disorder were compared using a χ2 test. A proportion ratio (PR) with a 95% confidence interval (CI) was calculated for each disease/health disorder. A logistic regression analysis was performed to examine the association between each disease/health disorder and health perception using gender, age, education, physical activity level, and smoking status as covariates. More than 50% of residents with each disease/health disorder reported their health to be good/very good/excellent. Residents with each disease/health disorder were less likely to have an accurate health perception than those without the corresponding disease/health disorder prior to (p < 0.001) and following adjustment of the covariates (p < 0.001). Our results suggest that overweight/obesity and prevalence of disease are not being recognized as unhealthy, which contradicts established definitions of health.
      PubDate: 2017-04-06
      DOI: 10.3390/sports5020023
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 24: Metabolic Power of Female Footballers in Various
           Small-Sided Games with Different Pitch Surfaces and Sizes

    • Authors: Jorge López-Fernández, Javier Sánchez-Sánchez, Leonor Gallardo, Jorge García-Unanue
      First page: 24
      Abstract: Small-sided-games (SSGs) seem to be a useful tool for replicating most types of scenarios found in sport competitions, but it is not that clear in female soccer. Game surface and pitch size seem to affect the intensity of SSGs, but no one has yet analysed the influence of these two variables together. The objective of this research was to analyse the metabolic power demands of various SSGs on possession play without goal-keepers, played on three different surfaces. Sixteen sub-elite female players performed three different four-a-side games (400 m2, 600 m2, and 800 m2) on three different surfaces (ground [GR]; natural grass [NG]; and artificial turf [AT]), recording a total of 96 events. Metabolic variables were recorded through a global positioning system (GPS). The GR condition obtained the lowest outputs for all variables in all of the SSGs. Furthermore, NG resulted in higher outcomes than AT for Average Metabolic Power (SSG 400 [+0.65; p = 0.019]; SSG 600 [+0.70; p = 0.04]); and equivalent distance (SSG 400 [+33.0; p = 0.02]; SSG 600 [+36.53; p = 0.04]). Moreover, SSG 400 obtained lower results than SSG 600 and SSG 800 for both AT and NG. In conclusion, playing on GR reduces the metabolic power of SSGs, While NG seems to be the most suitable surface for attaining highest metabolic responses for sub-elite female players. On the other hand, too big a pitch size may not increase the metabolic demands of the game.
      PubDate: 2017-04-17
      DOI: 10.3390/sports5020024
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 25: Effect of New Zealand Blackcurrant Extract on
           Repeated Cycling Time Trial Performance

    • Authors: Connor Murphy, Matthew Cook, Mark Willems
      First page: 25
      Abstract: New Zealand blackcurrant (NZBC) extract increased 16.1 km cycling time trial performance. The aim of the present study was to examine the effect of NZBC extract on 2 × 4 km time trial performance. Ten male cyclists (age: 30 ± 12 years, body mass: 74 ± 9 kg, height: 179 ± 7 cm, body fat: 11 ± 3%, (V̇) ̇O2max: 55 ± 7 mL•kg−1•min−1, mean ± SD) volunteered. Participants were familiarized with the time trials. Participants consumed capsulated NZBC extract (300 mg∙day−1 CurraNZ™; containing 105 mg anthocyanin) or placebo for seven days (double blind, randomised, cross-over design, wash-out at least seven days) before 2 × 4 km time trials (10 min active self-paced recovery between trials) (SRM ergometer, SRM International, Germany). Heart rate was recorded and blood lactate sampled immediately after each trial and 8 min into recovery between the trials. Times over comparable one km distances in each 4 km time trial were similar. No effect was observed for the time to complete the first (placebo: 380 ± 28 s, NZBC: 377 ± 27 s) and second 4 km of cycling (placebo: 391 ± 32 s, NZBC: 387 ± 30 s), within both groups the second 4 km times slower by 11 ± 8 s and 11 ± 9 s for placebo and NZBC, respectively. However, the total time of the two 4 km cycling trials was 0.82% faster with NZBC extract (placebo: 771 ± 60 s, NZBC 764 ± 56 s, p = 0.034) with seven participants having faster total times. There was no effect of NZBC on heart rate and lactate values at identical time points. New Zealand blackcurrant extract seems to be beneficial in repeated short-distance cycling time trials for overall performance.
      PubDate: 2017-05-09
      DOI: 10.3390/sports5020025
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 26: Injuries in Collegiate Women’s Volleyball: A
           Four-Year Retrospective Analysis

    • Authors: Christopher Sole, Ashley Kavanaugh, Michael Stone
      First page: 26
      Abstract: A four-year retrospective analysis of injury data was conducted on a collegiate (NCAA Division I) women’s volleyball team. Twenty athletes (Year 1: age = 19.4 ± 0.9 y, height = 175.2 ± 5.1 cm, body mass = 70.5 ± 10.2 kg; Year 2: age = 20.1 ± 1.0 y, height = 175.7 ± 4.7 cm, body mass = 69.5 ± 10.1 kg; Year 3: age = 20.1 ± 1.4 y, height = 173.8 ± 6.3 cm, body mass = 69.9 ± 10.8 kg; Year 4: age = 19.5 ± 1.4 y, height = 174.4 ± 8.6 cm, body mass = 72.7 ± 10.8 kg) participated in this study, accounting for 1483 total training exposures. Injury was defined as any damage to a body part, incurred during volleyball or strength and conditioning-related activities, which interfered with training and/or competition. Injury rate was normalized to the number of athletes and exposure and expressed as injuries per 1000 exposures. A total of 133 injuries were recorded. The most common injury was to the knee (left = 7.5%, right = 12.0%). Injuries occurred most often in volleyball practice (75.2%), followed by competition (20.3%), and strength and conditioning-related activities (4.5%). Non-contact injuries (upper body = 26.3%, lower body = 53.4%) were more common than contact injuries (upper-body = 13.5%, lower-body = 6.8%). An examination of injury rates relative to the training year revealed patterns in injury occurrence. Specifically, spikes in injury rate were consistently observed during periods of increased training volume that were preceded by breaks in organized training, such as the early pre-season and off-season training periods.
      PubDate: 2017-05-10
      DOI: 10.3390/sports5020026
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 27: Influence of Rest on Players’ Performance and
           Physiological Responses during Basketball Play

    • Authors: Robert Crowther, Anthony Leicht, Jessica Pohlmann, Jane Shakespear-Druery
      First page: 27
      Abstract: Pre-match warm-ups are standard in many sports but the focus has excluded the substitute players. The aim of this research was to investigate the result of inactivity on physiological and performance responses in substitute basketball players during competition. Two basketball players from the second tier of the State League of Queensland, Australia volunteered for this study and were assessed for performance (countermovement jump—CMJ) and physiological (core temperature via ingestible pill; skin temperature at the arm, chest, calf and thigh; heart rate—HR) responses prior to and following a 20-min warm-up, and during the first half of a competitive basketball match (2 × 20-min real time quarters). Warm up resulted in increases in CMJ (~7%), HR (~100 bpm) and core (~0.8 °C) and skin (~1.0 °C) temperatures. Following the warm up and during inactivity, substitute players exhibited a decrease in all responses including CMJ (~13%), HR (~100 bpm), and core (~0.5 °C) and skin (~2.0 °C) temperatures. Rest resulted in reductions in key performance and physiological responses during a competitive match that poses a risk for match strategies. Coaches should consider implementing a warm up to enhance core/skin temperature for substitute players immediately before they engage with competition to optimise player performance.
      PubDate: 2017-05-10
      DOI: 10.3390/sports5020027
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 28: Nutrition and Supplementation in Soccer

    • Authors: César Oliveira, Diogo Ferreira, Carlos Caetano, Diana Granja, Ricardo Pinto, Bruno Mendes, Mónica Sousa
      First page: 28
      Abstract: Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition).
      PubDate: 2017-05-12
      DOI: 10.3390/sports5020028
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 29: Exercise, Osteoporosis, and Bone Geometry

    • Authors: Amy Harding, Belinda Beck
      First page: 29
      Abstract: Exercise is commonly recommended in the prevention and management of osteoporosis. The most common method to monitor bone mass and its response to interventions is bone densitometry. While closely associated with risk of fracture, densitometry-derived areal bone mineral density (aBMD) does not provide a reliable indication of bone geometry or morphological adaptation to stimuli. In fact, the effects of exercise interventions on aBMD are frequently modest, and may not fully represent the benefit of exercise to bone. Animal models suggest that mechanical loading indeed influences bone geometry and thus strength. Such an effect in humans has the potential to reduce osteoporotic fracture. The aim of the current narrative review is to provide an overview of what is known about the effects of exercise on bone geometry, with a focus on relevance to osteoporosis.
      PubDate: 2017-05-12
      DOI: 10.3390/sports5020029
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 30: Acute Effects of Block Jumps in Female
           Volleyball Players: The Role of Performance Level

    • Authors: Javier Brazo-Sayavera, Pantelis Nikolaidis, Alba Camacho-Cardenosa, Marta Camacho-Cardenosa, Rafael Timón, Pedro Olivares
      First page: 30
      Abstract: Although the role of jumping ability in female volleyball players is well recognised, the effect of fatigue on this ability is not well known. The aim of the present study was to examine the effect of a series of block jumps (BJ) on jumping ability and whether it varies by performance level. Ten elite (EG) and 11 amateur (AG) female volleyball players performed a fatigue intervention consisting of 45 BJ, being tested for squat jump (SJ), countermovement jump (CMJ) and BJ before and after the intervention. Elasticity index (EI): (100 × (CMJ − SJ)/SJ) and upper limbs coordination index (ULCI): (100 × (BJ − CMJ)/CMJ) were calculated. After the intervention, EG showed a decrease of 4.40% in BJ height (p = 0.04; ES = 0.40), whereas AG presented an increase of 1.27%, which was not significant (p = 0.57; ES = 0.07). However, EG and AG presented no significant differences in SJ (p = 0.965 and p = 0.655) and CMJ (p = 0.742 and p = 0.211) when comparing baseline with post-intervention. Although EI and ULCI showed no significant differences after intervention in any group (AG: p = 0.989 and p = 0.114; EG: p = 0.242 and p = 0.205, respectively), AG presented a medium effect size (ES = 0.50) in EI and a small one in ULCI (ES = 0.37), also EG showed a medium-large effect in ULCI (ES = 0.75). These findings suggest that EG performance in BJ tends to decrease at the end of a specific jump training practice. Therefore, coaches and fitness trainers working with elite volleyball players should focus on exercises to maintain jumping ability during a match.
      PubDate: 2017-05-16
      DOI: 10.3390/sports5020030
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 31: Does Avalanche Shovel Shape Affect Excavation
           Time: A Pilot Study

    • Authors: Kurt Schindelwig, Alexander Hoffmann, Martin Mössner, Werner Nachbauer
      First page: 31
      Abstract: In Europe and North America, approximately 150 fatalities occur as a result of avalanches every year. However, it is unclear whether certain shovel shapes are more effective than others in snow removal during avalanche victim recovery. The objective was to determine the performance parameters with a developed standardized test using different shovel shapes and to determine sex-specific differences. Hence, several parameters were determined for clearing the snow from a snow filled box (15 men, 14 women). A flat (F) and a deep (D) shovel blade with the shaft connected straight (S) or in clearing mode (C) were used for the investigation of the shovel shapes FS, DC and the subsequent use of DC&DS. Mean snow mass shifted per unit time increased significantly from 1.50 kg/s with FS to 1.71 kg/s (14%) with DS and further to 1.79 kg/s (4%) with DC&DS for all participants. Snow mass shifted per unit time was 44% higher (p < 0.05) for men than for women. In excavation operations, the sex-specific physical performance should be taken into account. The results were limited to barely binding snow, because only with this snow did the tests show a high reliability.
      PubDate: 2017-05-23
      DOI: 10.3390/sports5020031
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 32: Effects of 12 Weeks of Tai Chi Chuan Training on
           Balance and Functional Fitness in Older Japanese Adults

    • Authors: Nobuo Takeshima, Mohammod Islam, Yoshiji Kato, Daisuke Koizumi, Makoto Narita, Nicole Rogers, Michael Rogers
      First page: 32
      Abstract: The purpose of this study was to determine the effects of Tai Chi Chuan on static and dynamic balance, and functional fitness in older adults. Forty-nine volunteers were divided into an exercise group (EX: 9 men and 16 women, average age 72 ± 5 years) and control group (13 men and 11 women, average age 73 ± 6 years). The EX participated in a 12-week supervised exercise program (60 min/day, 2 days/week) that consisted of 10-min warm-up and stretching, 40-min Tai Chi Chuan exercise (long-form Yang style with 108 movements), and 10-min cool-down/relaxation exercises. The control group was asked to not change their physical activity habits. Static (sway velocity standing on firm or foam surfaces with eyes open or closed) and dynamic balance (limits of stability (LOS)), as well as functional fitness measures of body mass; upper- and lower-body strength; and flexibility, mobility, and aerobic fitness were taken before and after the intervention. After the 12-week Tai Chi Chuan exercise program, there were no improvements in any functional fitness or balance variable although components of LOS tended to increase (13.1%, p = 0.052). These results indicate that 12 weeks of Tai Chi Chuan exercise has no significant effect on balance and functional fitness parameters in older Japanese adults.
      PubDate: 2017-05-26
      DOI: 10.3390/sports5020032
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 33: Relationships between Bat Swing Speed and Muscle
           Thickness and Asymmetry in Collegiate Baseball Players

    • Authors: Ryo Tsuchikane, Takatoshi Higuchi, Tadashi Suga, Michio Wachi, Jun Misaki, Daichi Tanaka, Yuto Miyake, Tadao Isaka
      First page: 33
      Abstract: The purpose of the present study was to examine the relationships between bat swing speed (BSS), muscle thickness, and muscle thickness asymmetry in collegiate baseball players. Twenty-four collegiate baseball players participated in this study. Maximum BSS in hitting a teed ball was measured using a motion capture system. The muscle thicknesses of the trunk (upper abdominal rectus, central abdominal rectus, lower abdominal rectus, abdominal wall, and multifidus lumborum), upper limb, and lower limb were measured using a B-mode ultrasonography. Lateral asymmetry between each pair of muscles was determined as the ratio of the thickness of the dominant side to that of the non-dominant side. Statistically significant positive correlations were observed between BSS and muscle thicknesses of the abdominal wall and multifidus lumborum on the dominant side (r = 0.426 and 0.431, respectively; p < 0.05), whereas only trends against this significance were observed between BSS and muscle thicknesses on the non-dominant side. No statistical correlations were found between BSS and the lateral asymmetry of any muscles. These findings indicate the importance of the trunk muscles for bat swing, and the lack of association between BSS and lateral asymmetry of muscle size.
      PubDate: 2017-06-02
      DOI: 10.3390/sports5020033
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 34: A Comparison of Implicit and Explicit Motor

    • Authors: Maliheh Sarabandi
      First page: 34
      Abstract: This study tends to assess implicit and explicit types of motor learning in patients with Multiple Sclerosis (MS) and normal peers by means of a serial reaction time. Sample size was 15 for each group and Samples included 30 patients with MS and 30 normal peers and were assigned to implicit and explicit learning groups. A repeated measures ANOVA was used for measuring reaction time and response error, and a paired samples t-test was used to compare regular and irregular sequence data in each group. Comparison of these two types of learning in speed (response time) and accuracy (number of errors) showed the number of errors (P = 0.012) and response time (P = 0.012) in the implicit motor learning group of MS patients and the number of errors (P = 0.096) and response time (P = 0.954) in the explicit motor learning group of MS patients. Moreover, comparison showed the number of errors (P = 0.008) and response time (P = 0.05) in the implicit group of normal peers and the number of errors (P = 0.011) and response time (P = 0.442) in the explicit group of normal peers. The results showed that explaining and describing the task is less effective at training the motor sequence of MS patients and that these patients benefit more from implicit learning.
      PubDate: 2017-06-07
      DOI: 10.3390/sports5020034
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 35: Muscular Power during a Lifting Task Increases
           after Three Months of Resistance Training in Overweight and Obese

    • Authors: Erika Zemková, Ol’ga Kyselovičová, Michal Jeleň, Zuzana Kováčiková, Gábor Ollé, Gabriela Štefániková, Tomáš Vilman, Miroslav Baláž, Timea Kurdiová, Jozef Ukropec, Barbara Ukropcová
      First page: 35
      Abstract: Background: This study evaluates the effect on power produced during a modified lifting task in the overweight and obese after three months of either resistance or aerobic training. Methods: Seventeen male subjects divided randomly into two groups performed deadlift and deadlift high pull, both with increasing weights up to maximal power, prior to and after the training programs (three sessions per week). Results: Their mean power increased significantly during the deadlift at 20 kg (14.3%, p = 0.026), 30 kg (17.7%, p = 0.008), 40 kg (16.5%, p = 0.011), 50 kg (14.5%, p = 0.020), and 60 kg (14.3%, p = 0.021) and during the deadlift high pull at 30 kg (9.9%, p = 0.037), 40 kg (10.1%, p = 0.035), and 50 kg (8.2%, p = 0.044) after the resistance training. However, the group that participated in the aerobic training failed to show any significant changes in power performance during either the deadlift or deadlift high pull. Conclusion: Three months of resistance training enhances power outputs during a lifting task with weights from 30 to 50 kg (~40%–60% of 1-repetition maximum) in the overweight and obese. Because this test was sensitive in revealing pre-post training changes in lifting performance, it should be implemented in the functional diagnostics for overweight and obese individuals and also complement existing testing methods.
      PubDate: 2017-06-08
      DOI: 10.3390/sports5020035
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 36: Ingestion of an Amino Acid Electrolyte Beverage
           during Resistance Exercise Does Not Impact Fluid Shifts into Muscle or

    • Authors: JohnEric Smith, Ben Krings, Timothy Peterson, Jaden Rountree, Roksana Zak, Matthew McAllister
      First page: 36
      Abstract: The purpose of this study was to investigate the impact of ingesting an amino acid-electrolyte (AAE) beverage during upper body resistance exercise on transient muscle hypertrophy, exercise performance, markers of muscle damage, and recovery. Participants (n = 15) performed three sets of six repetitions—bench press, lat pull down, incline press, and seated row—followed by three sets of eight repetitions at 75% of the estimated 1 repetition maximum—triceps kickback, hammer curl, triceps push down, and preacher curl—with 90 s of rest between sets. The final set of the push down/preacher curl was performed to failure. Prior to and immediately post-exercise, as well as 24, 48, and 72 h post exercise, cross-sectional muscle thickness was measured. Blood samples were collected prior to exercise, as well as 24, 48, and 72 h post-exercise for serum creatine kinase (CK) analysis. No treatment effect was found for muscle cross-sectional area, repetitions to failure, or serum CK. A main effect (p < 0.001) was observed in the change in serum CK levels in the days following the resistance exercise session. The findings of this study suggest that the acute ingestion of a AAE beverage does not alter acute muscle thickness, performance, perceived soreness and weakness, or markers of muscle damage.
      PubDate: 2017-06-10
      DOI: 10.3390/sports5020036
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 37: Functional Movement Screening and Paddle-Sport

    • Authors: Andrew Hatchett, Charles Allen, Jake St. Hilaire, Alex LaRochelle
      First page: 37
      Abstract: The purpose of the study reported here was to determine the relationship between an endurance paddle-sport athlete’s total functional movement screening (FMS) score and individual race performance. Fifty elite level endurance canoeists and kayakers completed the seven-stage FMS protocol prior to the 2016 United States Canoe and Kayak Association National Championship race. Time taken to finish the race was then associated to overall FMS score and respective sub-scores. Total FMS score and various sub-scores were significantly related to race performance. Female and male athletes differed in which sub-scores were shown to be significantly correlated to finishing time. Outcomes from this study indicate that limitations in functional movement are related to endurance paddle-sport race performance.
      PubDate: 2017-06-13
      DOI: 10.3390/sports5020037
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 38: What is Trained Develops! Theoretical
           Perspective on Skill Learning

    • Authors: Hermundur Sigmundsson, Leif Trana, Remco Polman, Monika Haga
      First page: 38
      Abstract: Knowledge about developmental theories is important for experts or specialists working with children following normal development and children who have various kinds of dysfunction, in order to better understand what happens with processes associated with motor behavior. In this article, we have explored how theories of development and learning can be used to understand processes associated with motor behavior. A probabilistic perspective emphasizes that the changes taking place in the development is a result of interaction: structural changes in the nervous system leading to changes in function and behavior and opposite, functional changes resulting in changes in structure. This bidirectional interaction between biological and experiential aspects is a continuous process which cannot be reduced to either organism or environment. Dynamical systems theory (DST) emphasizes that it is the interaction between the person, the environment, and the task that changes how our movements are, also in terms of how we develop and learn new movements. The interplay between these factors will, over time, lead to changes in motor development. The importance of experience is central to Edelman's theory of neuronal group selection (NGST). Activation of the nervous system increases the connections between certain areas of the brain, and the selection processes in the brain are a result of enhancement of neural connections involved in a "successful" motion. The central nervous system adapts its structure and function in response to internal and external influences, and hence neural plasticity is a prerequisite for learning and development. We argue that Edelman´s approach supports the theory of specificity of learning. From the perspectives of probabilistic epigenesis, DST, and NGST, we can see that being physically active and having the opportunity to get different movement experiences are of great significance for promoting motor development and learning. A variation of purposeful or rewarding physical activity in a variety of contexts will provide individual opportunities for changes of behavior in terms of both quantitative and qualitative changes in motor development.
      PubDate: 2017-06-15
      DOI: 10.3390/sports5020038
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 39: Prevalence of Injuries during Brazilian
           Jiu-Jitsu Training

    • Authors: Alex R. McDonald, Fred A. Murdock Jr., Josh A. McDonald, Christopher J. Wolf
      First page: 39
      Abstract: Brazilian jiu-jitsu (BJJ) is a martial art that focuses on groundwork, joint locks, and chokeholds. The purpose of this study is to determine the prevalence of injuries sustained during BJJ training. A 27-question research survey was e-mailed to 166 BJJ gyms in the United States. Demographic information, belt level, weight class, training hours, competition experience, and injury prevalence data were collected. The majority of respondents were Caucasian (n = 96) males (n = 121) with an average age of 30.3 years. Overall, the most common injury locations were to the hand and fingers (n = 70), foot and toes (n = 52), and arm and elbow (n = 51). The most common medically diagnosed conditions were skin infections (n = 38), injuries to the knee (n =26), and foot and toes (n = 19). The most common non-medically diagnosed injuries occurred to the hand and fingers (n = 56), arm and elbow (n = 40), and foot and toes (n = 33). In general, athletes were more likely to sustain distal rather than proximal injuries. Athletes reported more frequent medically diagnosed injuries to the lower extremity and more frequent self-diagnosed injuries to the upper extremity. Upper extremity injuries appear to be more frequent but less severe than lower extremity injuries with the opposite being true for lower extremity injuries.
      PubDate: 2017-06-12
      DOI: 10.3390/sports5020039
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 40: Active Recovery between Interval Bouts Reduces
           Blood Lactate While Improving Subsequent Exercise Performance in Trained

    • Authors: Harutiun M. Nalbandian, Zsolt Radak, Masaki Takeda
      First page: 40
      Abstract: This study aimed to examine the blood lactate and blood pH kinetics during high-intensity interval training. Seventeen well-trained athletes exercised on two different occasions. Exercises consisted of three 30 s bouts at a constant intensity (90% of peak power) with 4 min recovery between bouts followed by a Wingate test (WT). The recoveries were either active recovery (at 60% of the lactate threshold intensity) or passive recovery (resting at sitting position). During the exercise, blood samples were taken to determine blood gasses, blood lactate, and blood pH, and peak and average power were calculated for the WT. When performing the active recovery trials, blood pH was significantly higher (p < 0.01) and blood lactate was significantly lower (p < 0.01) compared with the passive recovery trials. WT performance was significantly higher in the active recovery trials: peak power was 671 ± 88 and 715 ± 108 watts, and average power was 510 ± 70 and 548 ± 73 watts (passive and active respectively; p < 0.01). However, no statistically significant correlations were found between the increased pH and the increased performance in the active recovery trials. These results suggest that active recovery performed during high-intensity interval exercise favors the performance in a following WT. Moreover, the blood pH variations associated with active recovery did not explain the enhanced performance.
      PubDate: 2017-06-12
      DOI: 10.3390/sports5020040
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 41: Link between Motor Competence and Health Related
           Fitness in Children and Adolescents

    • Authors: Carlos Luz, Rita Cordovil, Gabriela Almeida, Luis Rodrigues
      First page: 41
      Abstract: This study examined motor competence (MC) behavior in 6- to 14-year-old children, and investigated the differences in health-related fitness (HRF) between high and low MC groups, according to sex and age. A sample of 564 children (288 males) participated in this study, divided into three age groups (6–8 years; 9–11 years; 12–14 years). Total MC and its three components (stability, locomotor, and manipulative) were assessed with a quantitative instrument. HRF was evaluated using a maximal multistage 20-m shuttle-run test and the handgrip test. Participants were divided into tertiles according to their MC level and high and low MC groups were analyzed. Overall, MC increased across age groups for both sexes, but boys presented better results than girls. The high MC group outperformed their low MC peers in all HRF variables, independent of their age group. Although cardiovascular fitness increased with age for both the high and low MC groups, the differences between these groups were greater in older children compared to younger children, within the study age range. The findings suggest that MC interventions should be considered as an important strategy to enhance HRF, and girls at a young age should be a priority target.
      PubDate: 2017-06-15
      DOI: 10.3390/sports5020041
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 42: The Role of Eccentric Strength in 180°
           Turns in Female Soccer Players

    • Authors: Paul Jones, Christopher Thomas, Thomas Dos’Santos, John McMahon, Philip Graham-Smith
      First page: 42
      Abstract: Previous studies have reported an association between eccentric strength (ECC-STR) and change of direction (COD) ability. Little is known about how ECC-STR facilitates COD maneuvers. The aim of this study was to examine the role of ECC-STR during a 180° COD task in 18 female soccer players. Each player performed six trials of a 180° COD task whereby three-dimensional motion data from 10 Qualisys Pro-Reflex infrared cameras (240 Hz) and ground reaction forces (GRFs) from two AMTI force platforms (1200 Hz) were collected. Relative eccentric knee extensor (ECC-EXT) and flexor (ECC-FLEX) peak torque was collected from both limbs at 60°·s−1 using a Kin Com isokinetic dynamometer. Large correlations were revealed between COD performance (time to complete 5 m approach, 180° turn, 5 m return) and ECC-EXT (R = −0.674) and ECC-FLEX (R = −0.603). Moderate to large correlations were observed between approach velocity (AV) and COD performance (R = −0.484) and ECC-EXT (R = 0.724). Stronger participants (n = 9) recorded significantly (p < 0.05) faster AV (4.01 ± 0.18 vs. 3.74 ± 0.24 m·s−1, d = 1.27) and a greater reduction in velocity (−1.55 ± 0.17 vs. −1.37 ± 0.21 m·s−1, d = −0.94) during penultimate contact than weaker (n = 9) subjects. Greater ECC-STR is associated with faster COD performance in female soccer players, as stronger players are better able to decelerate during penultimate contact from faster approach velocities.
      PubDate: 2017-06-17
      DOI: 10.3390/sports5020042
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 43: The Relationship between Fundamental Motor Skill
           Proficiency and Participation in Organized Sports and Active Recreation in
           Middle Childhood

    • Authors: Stephanie Field, Viviene Temple
      First page: 43
      Abstract: Motor skill proficiency in middle childhood is associated with higher physical activity levels at that age and is predictive of adolescent physical activity levels. Much of the previous research in this area has used accelerometry in determining these relationships, and as a result, little is known about what physical activities the children are engaging in. Therefore the aim of this study was to examine rates of participation in physical activities, the relationships between motor proficiency and how often children participate, and if there were gender-based differences in participation, motor skills, or the relationship between these variables. Participants were 400 boys and girls (Mean age = 9 years 6 months) in grade 4. Motor skills were assessed using the Test of Gross Motor Development-2 (TGMD-2) and physical activity participation was measured using the Children’s Assessment of Participation and Enjoyment (CAPE). Descriptive statistics, chi-squared analyses, and multivariate analysis of variance (MANOVA) were used to examine activity patterns and whether these patterns differed by gender. Correlation coefficients were used to estimate the relationships between fundamental motor skill proficiency and participation. The boys and girls participated in many of the same activities, but girls were more likely to participate in most of the informal physical activities. More boys than girls participated in team sports, boys participated more frequently in team sports, and the boys’ object control and locomotor skill proficiency were significantly associated with participation in team sports. There were some significant associations between motor skills and participation in specific activities; however it is not clear if participation is developing skillfulness or those who are more skilled are engaging and persisting with particular activities.
      PubDate: 2017-06-18
      DOI: 10.3390/sports5020043
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 44: The Effect of Teaching Games of Understanding as
           a Coaching Instruction had on Adjust, Cover and Heart Rate among Malaysian
           and Indian Junior Hockey Players

    • Authors: Sanmuga Nathan
      First page: 44
      Abstract: The field hockey coaching process across both Malaysia and India favours a traditional, coach-centred approach of mastering technical skills in terms of game play parameters, fitness, intensity, and load training, whereas a tactical- and player-centred pedagogical approach still takes a backseat. On the other hand, the Teaching Games for Understanding (TGfU) model offers tactical-cognitive instruction and is gaining international recognition for its ability to produce intelligent players via a problem-solving approach in game play. Therefore, the purpose of this quasi-experimental study was to investigate the effect of TGfU compared to skill mastery instruction, termed as Skill Drill Technical (SDT), among Malaysian and Indian elite junior hockey players in term of the game play attributes of adjust and cover in 5 vs. 5 small-sided game play and game play intensity via heart rate (HR) at different points of game play. A total of n = 60 players with an average age of 15 ± 1.03 was selected via simple random sampling from both countries involved in this study and assigned equally to groups, with 15 per group for TGfU and for SDT across Malaysia and India. Gathered data were analysed using the ANOVA and ANCOVA techniques. Findings indicated that there were no significant differences for adjust in 5 vs. 5 game play between TGfU and SDT across Malaysia and India after the intervention. For cover, there was significant improvement for Malaysian players using the TGfU model compared to SDT. In contrast, there was no significant difference between these two models among the Indian players after the intervention. There was significant difference between these two models in terms of warm-up HR across the two countries, and HR was higher via TGfU. For HR immediately after the 5 vs. 5 game play intervention and HR after three minutes’ recovery, Indian players with TGfU recorded a higher and significant difference compared to SDT. However, findings indicated no significant difference between these two instruction types among Malaysians, although TGfU proved to have higher HR intensity. Therefore, these findings reiterated that TGfU is a useful approach for game play to enhance intensity and cardiac output. In conclusion, for TGfU to be more relevant to the coaching environment, future research should link game play and physiological parameters. TGfU should able to overcome the barriers of tradition and cultural background that may hinder its momentum.
      PubDate: 2017-06-20
      DOI: 10.3390/sports5020044
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 45: Energy Expenditure, Availability, and Dietary
           Intake Assessment in Competitive Female Dragon Boat Athletes

    • Authors: Jun Ong, Iain Brownlee
      First page: 45
      Abstract: Dragon boat racing requires high physical activity levels during competition and training. The female athletic triad refers to a number of negative health consequences (e.g., amenorrhoea, low bone mineral density, and low energy availability) that may result from high physical activity in female athletes in parallel with inadequate dietary intake. This study aimed to estimate energy expenditure and dietary adequacy in female competitive dragon boat athletes. Following ethical approval, energy expenditure was assessed by use of SensewearTM armbands (which measure movement as well as galvanic heat loss) on nine dragon boat athletes preparing for the Southeast Asian Games 2013. The mean estimated energy expenditure for the athletes was 2226 ± 711 kJ/day. Mean total energy, recorded using three-day food diaries (6715 ± 2518 kJ/day) and energy availability (99 ± 56 kJ/kg/day), were low. Estimated micronutrient intake (calcium 699.3 ± 328.7 mg/day and iron 10.6 ± 4.7 mg/day) did not meet recommended daily allowances of 800 mg/day and 19 mg/day, respectively. The low intake of energy, calcium, and iron noted within this study could have negative effects on performance and short- and long-term health in female dragon boat athletes.
      PubDate: 2017-06-21
      DOI: 10.3390/sports5020045
      Issue No: Vol. 5, No. 2 (2017)
  • Sports, Vol. 5, Pages 2: Content Validity and Psychometric Properties of
           the Nomination Scale for Identifying Football Talent (NSIFT): Application
           to Coaches, Parents and Players

    • Authors: Alejandro Prieto-Ayuso, Juan Pastor-Vicedo, Onofre Contreras-Jordán
      First page: 2
      Abstract: The identification of football talent is a critical issue both for clubs and the families of players. However, despite its importance in a sporting, economic and social sense, there appears to be a lack of instruments that can reliably measure talent performance. The aim of this study was to design and validate the Nomination Scale for Identifying Football Talent (NSIFT), with the aim of optimising the processes for identifying said talent. The scale was first validated through expert judgment, and then statistically, by means of an exploratory factor analysis (EFA), confirmatory factor analysis (CFA), internal reliability and convergent validity. The results reveal the presence of three factors in the scale’s factor matrix, with these results being confirmed by the CFA. The scale revealed suitable internal reliability and homogeneity indices. Convergent validity showed that it is teammates who are best able to identify football talent, followed by coaches and parents. It can be concluded that the NSIFT is suitable for use in the football world. Future studies should seek to confirm these results in different contexts by means of further CFAs.
      PubDate: 2017-01-01
      DOI: 10.3390/sports5010002
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 3: Effect of Number of Players and Maturity on
           Ball-Drills Training Load in Youth Basketball

    • Authors: Daniele Conte, Terence Favero, Meike Niederhausen, Laura Capranica, Antonio Tessitore
      First page: 3
      Abstract: This study aimed to assess the basketball ball-drills workload analyzing: (1) the effect of varying the number of players involved on physiological and technical demands; (2) the temporal changes in players’ responses across bouts; and (3) the relationship of players’ workload with their maturation status and training age. Twelve young male basketball players (mean ± SD; age 13.9 ± 0.7 years; height 1.76 ± 0.06 m; body mass 65.7 ± 12.5 kg; HRmax 202 ± 8 beat·min−1) completed three bouts of 4 min interspersed by 2 min of passive recovery of two vs. two and four vs. four ball-drills. The mean percentage of HRmax (%HRmax) and ratings of perceived exertion (RPE) were collected. Technical actions (TAs) (dribbles, passes, shots, interceptions, steals, rebounds, and turnovers) were calculated through notational analysis. Players’ genitalia development (GD) and pubic hair (PH) growth were assessed using Tanner scale. Results showed a higher %HRmax (p = 0.018), RPE (p = 0.042), dribbles (p = 0.007), shots (p = 0.003), and rebounds (p = 0.006) in two vs. two compared to four vs. four condition. Furthermore, a statistical difference was found for %HRmax (p = 0.005) and number of passes (p = 0.020) between bouts. In addition, no correlation between GD, PH, and training age with %HRmax, RPE, and TAs was found. These findings suggest that variations of the number of players involved affect ball-drills workload and that ball-drills training intensity varies across bouts. Finally, ball-drills elicit an adequate training stimulus, regardless of players’ maturation status and training age.
      PubDate: 2017-01-02
      DOI: 10.3390/sports5010003
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 4: Poorer Intermittent Sprints Performance in
           Ramadan-Fasted Muslim Footballers despite Controlling for Pre-Exercise
           Dietary Intake, Sleep and Training Load

    • Authors: Abdul Aziz, Ahmad Che Muhamad, Siti Roslan, Nazirah Ghulam Mohamed, Rabindarjeet Singh, Michael Chia
      First page: 4
      Abstract: This study examines the effects of Ramadan fasting on sprint performance during prolonged intermittent exercise in trained Muslim footballers, under controlled pre-exercise conditions. A within-group, cross-over study design with two non-fasted or Control trials performed before (i.e., CON1) and after (CON2) the Ramadan month, and with the Ramadan-fasted (RAM) trials performed within the Ramadan month. After familiarization, 14 players completed a modified 60-min (4 × 15-min exercise blocks interspersed with 3-min intervals) of the Loughborough Intermittent Shuttle Test (mLIST) of fixed speeds of walking, jogging, running, but with all-out effort sprints. During the interval periods, capillary blood glucose and blood lactate measures were taken, rectal and skin temperatures were recorded and maximal voluntary isometric contractions (MVIC) of the dominant leg and hand-grip were performed to provide some indication to the cause(s) of ‘fatigue’ during exercise. Players were provided with standardized 24-h pre-packed meals prior to all trials. Sleep hours were objectively assessed and perceived training loads were monitored and these were equivalent between RAM and CON trials. Sprint times throughout mLIST were significantly faster in both CON1 and CON2 as compared to RAM trials (all P < 0.017; d = small to moderate), and this poorer performance in RAM was observed as early as during the first 15-min of the mLIST. Blood markers, MVIC and thermoregulatory results were not substantially different between both CON and RAM trials. In conclusion, despite similarities in dietary intake, sleeping hours and training loads between conditions, results still indicate that Ramadan fasting had an adverse effect on prolonged intermittent performance. Nocebo effects plays a dominant role during exercise in the Ramadan-fasted state.
      PubDate: 2017-01-06
      DOI: 10.3390/sports5010004
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 5: Soccer and Relative Age Effect: A Walk among
           Elite Players and Young Players

    • Authors: Manuel Sierra-Díaz, Sixto González-Víllora, Juan Pastor-Vicedo, Jaime Serra-Olivares
      First page: 5
      Abstract: Grouping people according to chronological age is popular in fields such as education and sport. Athletes who are born in the first months of the year usually have cognitive and physical development differences in contrast to those born in the last months of the same year. That is why competitive teams tend to select older players more often than youngsters. Age differences between athletes born in the same year as well as an over-representation of older players are known as the Relative Age Effect. This effect is extensively described in young and elite team sports such as basketball, volleyball or, ice-hockey, as well as in soccer. The purpose of this study is to examine the state-of-the-art of the Relative Age Effect in youth and elite soccer players. This review summarizes recent research articles on the Relative Age Effect related to competitive soccer from 2010 to 2016. The systematic literature search was conducted in four databases: SPORTDiscus, Medline, EBSCO host and Google Scholar. Although causes and final solutions have not been clearly achieved yet, it is necessary to continue investigating this phenomenon in order to provide a starting point for future research.
      PubDate: 2017-01-11
      DOI: 10.3390/sports5010005
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 6: Acknowledgement to Reviewers of Sports in 2016

    • Authors: Sports Editorial Office
      First page: 6
      Abstract: The editors of Sports would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2016. [...]
      PubDate: 2017-01-12
      DOI: 10.3390/sports5010006
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 7: Effect of Post-Exercise Whole Body Vibration with
           Stretching on Mood State, Fatigue, and Soreness in Collegiate Swimmers

    • Authors: Justin Merrigan, Matthew Tynan, Jonathan Oliver, Andrew Jagim, Margaret Jones
      First page: 7
      Abstract: Static stretching (SS) during whole body vibration (WBV) has been suggested for exercise recovery. The purpose was to compare post-exercise self-ratings of fatigue (FAT), mood state (BAM), soreness (SOR), and perceived exertion (RPE) between SS and WBV+SS in swimmers (9 women, mean ± SD: 19.3 ± 1.3 year, 171 ± 5.7 cm, 67.6 ± 7.2 kg, 26.6 ± 4.1 %body fat (%BF); 10 men, mean ± SD: 19.7 ± 1.0 year, 183 ± 5.5 cm, 77.1 ± 4.2 kg, 13.1 ± 2.2 %BF). Athletes were divided by sex, event (sprint, distance), and assigned to SS or WBV+SS. Both conditions consisted of SS performed on the WBV platform with or without WBV (50 Hz, 6 mm). Sessions consisted of: pre and post measures of BAM, FAT, SOR; the condition; and RPE. Mixed factorial ANOVA were run. A significant condition by pre/post interaction was observed (p = 0.035). Post hoc analyses showed WBV+SS elicited lower post-exercise ratings of FAT (p = 0.002) and the BAM affective states, of tension (p = 0.031), and fatigue (p = 0.087). RPE did not differ between conditions. Of interest is the decrease in tension and fatigue noted by the BAM. Mood state can be indicative of how athletes adapt to training volume and intensity.
      PubDate: 2017-01-13
      DOI: 10.3390/sports5010007
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 8: Sex Differences in Countermovement Jump Phase

    • Authors: John McMahon, Sophie Rej, Paul Comfort
      First page: 8
      Abstract: The countermovement jump (CMJ) is commonly used to explore sex differences in neuromuscular function, but previous studies have only reported gross CMJ measures or have partly examined CMJ phase characteristics. The purpose of this study was to explore differences in CMJ phase characteristics between male and female athletes by comparing the force-, power-, velocity-, and displacement-time curves throughout the entire CMJ, in addition to gross measures. Fourteen men and fourteen women performed three CMJs on a force platform from which a range of kinetic and kinematic variables were calculated via forward dynamics. Jump height (JH), reactive strength index modified, relative peak concentric power, and eccentric and concentric displacement, velocity, and relative impulse were all greater for men (g = 0.58–1.79). Relative force-time curves were similar between sexes, but relative power-, velocity-, and displacement-time curves were greater for men at 90%–95% (immediately before and after peak power), 47%–54% (start of eccentric phase) and 85%–100% (latter half of concentric phase), and 65%–87% (bottom of countermovement and initial concentric phase) of normalized jump time, respectively. The CMJ distinguished between sexes, with men demonstrating greater JH through applying a larger concentric impulse and, thus, achieving greater velocity throughout most of the concentric phase, including take-off.
      PubDate: 2017-01-19
      DOI: 10.3390/sports5010008
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 9: Functional Assessment and Injury Risk in a
           Professional Soccer Team

    • Authors: Pedro Gómez-Piqueras, Sixto González-Víllora, María Sainz de Baranda Andújar, Onofre Contreras-Jordán
      First page: 9
      Abstract: At the last World Conference on Sport and Physical Therapy celebrated in Bern (Switzerland, 2015), it was confirmed that the functional skills of an athlete are a very important variable to be considered in the recovery of an injury. On the other hand, its use as a predictive risk tool still lacks solid evidence. The purpose of this study was to determine whether a battery of functional tests (FPT) could be used as a preliminary measure for the season in order to identify the injury risk in a professional soccer team in the Spanish Second Division B League. Fifty-two soccer players (ages of 25.3 ± 4.6 years, 10.33% ± 0.9% fat) were functionally assessed during two seasons (2012–2013 and 2013–2014) and analyzed from an injury perspective. A total of 125 injuries were recorded. The sample was grouped based on the number of injuries and the required absence days. Except for the bipodal vertical jump (CMJ), none of the functional tests revealed differences among the groups. The correlation study between the functional condition and the suffered injuries did not show any significant results.
      PubDate: 2017-01-22
      DOI: 10.3390/sports5010009
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 10: Change of Muscle Activity as Well as Kinematic
           and Kinetic Parameters during Headers after Core Muscle Fatigue

    • Authors: Stephan Becker, Michael Fröhlich, Jens Kelm, Oliver Ludwig
      First page: 10
      Abstract: In soccer, headers are a tactical measure and influenced by numerous factors. The goal of this study was to identify whether changes in kinematics and muscular activity, especially of the head-stabilizing muscles, occur during headers when the core musculature is fatigued. In two subgroups, muscular activity (12 amateur players, age 23.6 ± 4.2 years) and kinematics and dynamics (29 amateur players, age 23.7 ± 2.8 years) were examined during straight headers on a pendulum header. Data were collected before and after the core muscles were fatigued by an exercise program. Telemetric surface EMG, 3D acceleration sensor, force plate, and video recordings were used. Under fatigue, the activity of M. erector spinae and M. rectus abdominis was significantly reduced in the preparation phase of the header. The activity of M. sternocleidomastoideus was significantly increased during the jump phase, and the hip extension angle during maximum arched body tension was significantly reduced under fatigue. Jumping height, acceleration force impulse, and linear head acceleration were also significantly reduced. We conclude that fatigue of the core muscles affects the motion technique of the header and the activity of the muscle groups stabilizing the head. Therefore, the necessity of specific training in soccer should be emphasized from a medical-preventive point of view.
      PubDate: 2017-01-22
      DOI: 10.3390/sports5010010
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 11: Use of Non-Steroidal Anti-Inflammatory Drugs
           among Participants in a Mountain Ultramarathon Event

    • Authors: Sonia Martínez, Antoni Aguiló, Carlos Moreno, Leticia Lozano, Pedro Tauler
      First page: 11
      Abstract: The aim of this study was to evaluate and compare the prevalence of non-steroidal anti-inflammatory drugs (NSAID) consumption immediately before, during and immediately after three mountain ultra-endurance runs that differed in their course distance. This observational study took place at the Ultra Mallorca Serra de Tramuntana (Mallorca, Spain), an ultra-endurance mountain event with runners participating either in a 112-km (Ultra, n = 58), a 67-km (Trail, n = 118) or a 44-km (Marathon, n = 62) run competition. Participants in the study answered, within an hour after finishing the competition, a questionnaire focused mainly on NSAIDs consumption. Among study participants, 48.3% reported taking NSAIDs at least for one of the time-points considered: before, during and/or immediately after the competition, with more positive responses (having taken medication) found for the Ultra (60.3%) than for the Trail (49.2%) and the Marathon (35.5%). Among consumers, the Ultra participants reported the lowest intake before and the highest during the race, while participants in the Marathon reported similar consumption levels before and during the race. In conclusion, a high prevalence of NSAID consumption was found among athletes participating in an ultra-endurance mountain event. Competition duration seemed to determine both the prevalence and the chronological pattern of NSAID consumption.
      PubDate: 2017-01-29
      DOI: 10.3390/sports5010011
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 12: Seasonal Variation of Agility, Speed and
           Endurance Performance in Young Elite Soccer Players

    • Authors: Michal Dragijsky, Tomas Maly, Frantisek Zahalka, Egon Kunzmann, Mikulas Hank
      First page: 12
      Abstract: The aim of this study was to investigate changes in the linear running speed (LRS) for 30 m, change of direction speed (CODS), and endurance in young elite Czech soccer players. The following tests were conducted to assess CODS and endurance: Agility 505 turning toward the dominant (A505DL) and non-dominant lower limb (A505NL); Illinois Agility Test (IAT); and intermittent test (Yo-Yo IRT1). During the soccer season, we investigated performance at the following time periods: the start (t1) and the end of the pre-season period (t2); during (t3) and at the end of the competitive period (t4). Repeated measurement analysis of variance revealed a significant effect of time period on selected fitness parameters (p < 0.05). Post hoc analysis for test A505DL revealed significant improvements of performance at t3 (2.71 ± 0.08 s) and t4 (2.72 ± 0.06 s) compared to t1 (2.81 ± 0.09 s). A505NL was significantly different between t1 (2.83 ± 0.09 s) and t2 (2.76 ± 0.09 s), t3 (2.7 ± 0.07 s) and t4 (2.71 ± 0.09 s). Performance of CODS at t1 for the IAT (18.82 ± 0.56 s) was significantly lower (p < 0.05) than any other time period (t2 = 18.52 ± 0.63 s, t3 = 17.94 ± 0.51 s, t4 = 17.89 ± 0.66 s). The power of LRS was significantly different at t3 (4.99 ± 0.15 s), and t4 (4.98 ± 0.17 s) compared to t1 (5.15 ± 0.21 s), and t2 (5.07 ± 0.14 s). For the Yo-Yo IRT1 test, we observed a significant increase in performance between t1 (625.26 ± 170.34 m), t2 (858.95 ± 210.55 m), and t3 (953.68 ± 229.88 m). These results show the impact of soccer season time period on young soccer player performance and may further serve as a basis for comparison with similar research conducted by peers. These results may aid sports practice for clinicians, conditioning coaches, soccer coaches and physiotherapeutic coaches.
      PubDate: 2017-02-04
      DOI: 10.3390/sports5010012
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 13: The Influence of Exercise Training on Quality of
           Life and Psychosocial Functioning in Children with Congenital Heart
           Disease:A Review of Intervention Studies

    • Authors: Karolijn Dulfer, Willem Helbing, Elisabeth Utens
      First page: 13
      Abstract: Children and adolescents operated upon for congenital heart disease may show reduced exercise capacity and physical activity, associated with lowered quality of life. This review presents intervention studies on the influence of an exercise program on quality of life and psychosocial functioning in children with severe congenital heart disease. Participation in an exercise program among young people with complex congenital heart disease seemed to have positive effects on quality of life and passive leisure time spent. However, more effects of the exercise programs may have been expected. For future research it is important to critically evaluate the content of the exercise programs.
      PubDate: 2017-02-10
      DOI: 10.3390/sports5010013
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 14: Differences in the Dominant and Non-Dominant
           Knee Valgus Angle in Junior Elite and Amateur Soccer Players after
           Unilateral Landing

    • Authors: Oliver Ludwig, Steven Simon, Joe Piret, Stephan Becker, Franz Marschall
      First page: 14
      Abstract: More than 70% of all knee injuries in soccer occur in non-contact situations. It is known that increased lower limb dynamic knee valgus is associated with such situations. Little has been found out about differences in knee kinematics of the dominant (kicking) and non-dominant (supporting) leg during a single leg landing. A total of 114 male adolescent soccer players (age 14.6 ± 1.1 years) from elite (N = 66) and amateur soccer clubs (N = 48) performed a single leg drop landing down from a box. For each leg, the two-dimensional dynamic knee valgus angle (DKVA) was calculated. Paired t-tests were used to statistically determine significant differences between dominant and non-dominant leg DKVA, and t-tests were calculated between the two performance groups. Statistically significant differences (p < 0.05) were identified for the DKVA between the dominant and non-dominant leg for both amateur and elite players, showing a greater DKVA for the dominant leg. Group differences for the DKVA between amateur and elite players were not found, neither for the dominant, nor for the non-dominant leg. It can be concluded that the non-dominant leg showed more stable dynamics than the dominant leg during unilateral landing regardless of the player’s performance level. This could be due to adaptions to sport-specific requirements. Therefore, it is recommended that programs to prevent knee injuries among soccer players consider the dynamics of each leg individually.
      PubDate: 2017-02-13
      DOI: 10.3390/sports5010014
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 15: Between-Session Reliability of Common Strength-
           and Power-Related Measures in Adolescent Athletes

    • Authors: Christopher Thomas, Thomas Dos’Santos, Paul Comfort, Paul Jones
      First page: 15
      Abstract: The purpose of this study was to investigate the between-session reliability of common strength- and power-related measures in adolescent athletes. Seventeen adolescent athletes (males: n = 8: age 17.1 ± 2.2 years; height 175.6 ± 3.5 cm; mass 80.2 ± 3.6 kg; females: n = 9; age 16.9 ± 2.6 years; height 178.5 ± 4.3 cm; mass 71.5 ± 4.5 kg) participated in this study. Isokinetic dynamometry, isometric mid-thigh pull (IMTP), countermovement jump (CMJ), and horizontal jumps (standing broad jump (SBJ) and single-leg hop (SLH)) were each performed twice on separate days, seven days apart. Reliability was assessed by intraclass correlation coefficient (ICC), coefficient of variation (%CV), standard error of measurement (SEM), and smallest detectable difference (SDD). Intraclass correlation coefficients and CV demonstrated acceptable between-session reliability for all measures (ICC > 0.63; CV < 11%), except rate of force development and impulse measures during bilateral and unilateral stance IMTP. Smallest detectable differences demonstrated that changes in performance of >7% CMJ height, >8% SLH distance, >10% in peak isometric force, and >5% in isokinetic peak torques should be considered meaningful, when assessing adolescent athletes.
      PubDate: 2017-02-14
      DOI: 10.3390/sports5010015
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 16: Functional Movement Screen Scores and Physical
           Performance among Youth Elite Soccer Players

    • Authors: Bruno Silva, Filipe Clemente, Miguel Camões, Pedro Bezerra
      First page: 16
      Abstract: This study had two main objectives: (1) to determine if differences in Functional Movement Screen (FMS) scores exist between two levels of competition; and (2) to analyze the association between FMS individual and overall scores and physical performance variables of lower-limb power (jumps), repeated sprint ability and shot speed. Twenty-two Under 16 (U16) and twenty-six Under 19 (U19) national competitive soccer players participated in this study. All participants were evaluated according to anthropometrics, FMS, jump performance, instep kick speed and anaerobic performance. There were no significant differences in the individual FMS scores between competitive levels. There were significant negative correlations between hurdle step (right) and Running-based Anaerobic Sprint Test (RAST) power average ( ρ = −0.293; p = 0.043) and RAST fatigue index (RAST FatIndex) ( ρ = −0.340; p = 0.018). The hurdle step (left) had a significant negative correlation to squat jump (SJ) ( ρ = −0.369; p = 0.012). Rotary stability had a significant negative correlation to RAST fatigue index (Right: ρ = −0.311; p = 0.032. Left: ρ = −0.400; p = 0.005). The results suggest that individual FMS scores may be better discriminants of performance than FMS total score and established minimal association between FMS scores and physical variables. Based on that, FMS may be suitable for the purposes of determining physical function but not for discriminating physical performance.
      PubDate: 2017-02-21
      DOI: 10.3390/sports5010016
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 17: Body Composition Evaluation Issue among Young
           Elite Football Players: DXA Assessment

    • Authors: César Leão, Mário Simões, Bruno Silva, Filipe Clemente, Pedro Bezerra, Miguel Camões
      First page: 17
      Abstract: Accurate assessment of body composition is an important issue among athletes. Different methodologies generate controversial results, leading to a deep uncertainty on individual exercise prescriptions. Thus, this study aims to identify the differences between field methods, such as bioelectrical impedance (BIA) and skinfold assessment, with a clinical method, highly accurate, dual-energy X-ray absorptiometry (DXA), among elite young football players. Thirty-eight male football players with a mean (sd) age of 16.7 (0.87) years, involved in the Portuguese national competition of U16 (n = 13) and U19 (n = 25), were evaluated and objective measures of body composition, muscle strength and football skills were collected by trained specialists. Body composition was assessed using BIA (Tanita BC-418, Tanita Corp., Tokyo, Japan), in agreement with all the evaluation premises. Additionally, all athletes were evaluated using the clinical method DXA (Hologic Inc., Waltham, MA, USA). Among the U19 athletes, three skinfold sites (SKF) were assessed: chest, abdomin and thigh. The Spearman correlation coefficients and the mean difference between methods were calculated. The agreement between both methods was analyzed using Bland-Altman plots. Among the evaluated athletes, lower mean values of body fat % were found using BIA as a method of body composition assessment compared with DXA (12.05 vs. 15.58 for U16; 11.97 vs. 14.16 for U19). Despite the moderate correlation between methods (r = 0.33) to estimate the percentage of total fat, the median of the difference (DXA vs. BIA) was relevant in clinical terms, with 2.90% and 1.47% for U16 and U19 athletes, respectively. Stronger correlations were found between the sum of the SKF and DXA fat estimation (r = 0.68). The Bland-Altman plots showed a clear underestimation in the evaluations using the BIA, namely among athletes with better body composition profiles (8%–12% of fat). Using BIA, an underestimation of body fat assessment was observed among 94.5% of the athletes with less than 12% body fat mass. Among the evaluated athletes, fat mass was underestimated at a median value of 2.21% using BIA in comparison with DXA. The sum of the SKF showed a stronger correlation with the reference method (DXA) (r = 0.68) than BIA.
      PubDate: 2017-02-23
      DOI: 10.3390/sports5010017
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 18: Effect of Ball Weight on Speed, Accuracy, and
           Mechanics in Cricket Fast Bowling

    • Authors: Katharine Wickington, Nicholas Linthorne
      First page: 18
      Abstract: The aims of this study were: (1) to quantify the acute effects of ball weight on ball release speed, accuracy, and mechanics in cricket fast bowling; and (2) to test whether a period of sustained training with underweight and overweight balls is effective in increasing a player’s ball release speed. Ten well-trained adult male cricket players performed maximum-effort deliveries using balls ranging in weight from 46% to 137% of the standard ball weight (156 g). A radar gun, bowling target, and 2D video analysis were used to obtain measures of ball speed, accuracy, and mechanics. The participants were assigned to either an intervention group, who trained with underweight and overweight balls, or to a control group, who trained with standard-weight balls. We found that ball speed decreased at a rate of about 1.1 m/s per 100 g increase in ball weight. Accuracy and bowling mechanics were not adversely affected by changes in ball weight. There was evidence that training with underweight and overweight balls might have produced a practically meaningful increase in bowling speed (>1.5 m/s) in some players without compromising accuracy or increasing their risk of injury through inducing poor bowling mechanics. In cricket fast bowling, a wide range of ball weight might be necessary to produce an effective modified-implement training program.
      PubDate: 2017-02-28
      DOI: 10.3390/sports5010018
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 19: Neck Cooling Improves Table Tennis Performance
           amongst Young National Level Players

    • Authors: Terun Desai, Lindsay Bottoms
      First page: 19
      Abstract: This study aimed to examine the effects of neck cooling on table tennis performance. Eight young, National level, male table tennis players (age 16 ± 2 years, height 1.77 ± 0.08 m, body mass 67.54 ± 10.66 kg) were recruited. Participants attended four testing sessions separated by a week. Session one determined fitness levels, and session two was a familiarisation trial. The final two sessions involved completing the table tennis-specific protocol either with (ICE) or without (CON) neck cooling for 1 min before each exercise period (bout: 80–90 shots), which represented an individual game. The exercise protocol required completing three bouts to represent a match, each simulating a different skill (forehand, backhand, alternate forehand and backhand), against a mechanical ball thrower. Performance was measured by the number of balls hitting two pre-determined targets. Heart rate, ratings of perceived exertion (RPE), and thermal sensation (TS) were measured. Total performance scores (shots on target) were significantly greater during ICE (136 ± 26), compared to CON (120 ± 25; p = 0.006) with a 15 (±12)% improvement. Effects for time (p < 0.05) but not condition (p > 0.05) were found for RPE and all other physiological variables. TS significantly decreased with cooling throughout the protocol (p = 0.03). Neck cooling appears to be beneficial for table tennis performance by lowering thermal sensation.
      PubDate: 2017-03-11
      DOI: 10.3390/sports5010019
      Issue No: Vol. 5, No. 1 (2017)
  • Sports, Vol. 5, Pages 20: Detection and Selection of Behavioral Patterns
           Using Theme: A Concrete Example in Grassroots Soccer

    • Authors: Mario Amatria, Daniel Lapresa, Javier Arana, M. Anguera, Gudberg Jonsson
      First page: 20
      Abstract: Observational methodology provides a rigorous yet flexible framework for capturing behaviors over time to allow for the performance of subsequent diachronic analyses of the data captured. Theme is a specialized software program that detects hidden temporal behavioral patterns (T-patterns) within data sets. It is increasingly being used to analyze performance in soccer and other sports. The aim of this study was to show how to select and interpret T-patterns generated by the application of three “quantitative” sort options in Theme and three “qualitative” filters established by the researchers. These will be used to investigate whether 7-a-side (F7) or 8-a-side (F8) soccer is best suited to the learning and skills development needs of 7- and 8-year-old male soccer players. The information contained in the T-patterns generated allowed us to characterize patterns of play in children in this age group. For both formats, we detected technical-tactical behaviors showing that children of this age have difficulty with first-touch actions and controlling the ball after a throw-in. We also found that ball control followed by a pass or a shot at the goal are common in the central corridor of the pitch. Further, depth of play is achieved by ball control, followed by dribbling and a pass or shot. In F8, we saw that depth of play was achieved through ball control, followed by dribbling and passing of one or more opponents leading to a pass or shot. However, in F7, we saw that players succeeded in advancing from their goal area to the rival goal area through a sequence of actions.
      PubDate: 2017-03-13
      DOI: 10.3390/sports5010020
      Issue No: Vol. 5, No. 1 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
Home (Search)
Subjects A-Z
Publishers A-Z
Your IP address:
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-