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   ISSN (Online) 2075-4663
   Published by MDPI Homepage  [148 journals]
  • 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 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)
  • Sports, Vol. 5, Pages 1: Empirical Prediction of Turnovers in NFL Football

    • Authors: Joel Bock
      First page: 1
      Abstract: Turnovers in the National Football League (NFL) occur whenever a team loses possession of the ball due to a fumble, or an interception. Turnovers disrupt momentum of the offensive team, and represent lost opportunities to advance downfield and score. Teams with a positive differential turnover margin in a given game win 70 % of the time. Turnovers are statistically rare events, occurring apparently randomly. These characteristics make them difficult to predict. This investigation advances the hypothesis that turnovers are predictable in NFL football. Machine learning models are developed to learn the concept: At any point within a football game, what is the likelihood that a turnover will be observed on the next play from scrimmage? NFL play-by-play data for 32 teams spanning seven full seasons were used to train the models. Results presented suggest evidence to support the working hypothesis. Under certain conditions, both fumbles and interceptions can be anticipated at low false discovery rates (less than 15 % ). When a turnover is predicted on the impending play from scrimmage, a high degree of confidence is associated with that prediction. The ability to anticipate catastrophic in-game events may lead to their management and control, ultimately improving the performance of individual athletes and their teams. This investigation contributes to the sports science literature by demonstrating the predictability of in-game events often considered to be essentially random in their occurrence. To the author’s knowledge, direct prediction of turnovers has not previously appeared in the literature, which has focused on retrospective statistical analyses of turnover margin in football games.
      PubDate: 2016-12-29
      DOI: 10.3390/sports5010001
      Issue No: Vol. 5, No. 1 (2016)
  • Sports, Vol. 4, Pages 46: Airflow-Restricting Mask Reduces Acute
           Performance in Resistance Exercise

    • Authors: Yuri Motoyama, Gustavo Joel, Paulo Pereira, Gilmar Esteves, Paulo Azevedo
      First page: 46
      Abstract: Background: The aim of this study was to compare the number of repetitions to volitional failure, the blood lactate concentration, and the perceived exertion to resistance training with and without an airflow-restricting mask. Methods: Eight participants participated in a randomized, counterbalanced, crossover study. Participants were assigned to an airflow-restricting mask group (MASK) or a control group (CONT) and completed five sets of chest presses and parallel squats until failure at 75% one-repetition-maximum test (1RM) with 60 s of rest between sets. Ratings of perceived exertion (RPEs), blood lactate concentrations (Lac−), and total repetitions were taken after the training session. Results: MASK total repetitions were lower than those of the CONT, and (Lac−) and MASK RPEs were higher than those of the CONT in both exercises. Conclusions: We conclude that an airflow-restricting mask in combination with resistance training increase perceptions of exertion and decrease muscular performance and lactate concentrations when compared to resistance training without this accessory. This evidence shows that the airflow-restricting mask may change the central nervous system and stop the exercise beforehand to prevent some biological damage.
      PubDate: 2016-09-23
      DOI: 10.3390/sports4040046
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 47: Muscle- and Mode-Specific Responses of the
           Forearm Flexors to Fatiguing, Concentric Muscle Actions

    • Authors: Ethan Hill, Terry Housh, Cory Smith, Richard Schmidt, Glen Johnson
      First page: 47
      Abstract: Background: Electromyographic (EMG) and mechanomyographic (MMG) studies of fatigue have generally utilized maximal isometric or dynamic muscle actions, but sport- and work-related activities involve predominately submaximal movements. Therefore, the purpose of the present investigation was to examine the torque, EMG, and MMG responses as a result of submaximal, concentric, isokinetic, forearm flexion muscle actions. Methods: Twelve men performed concentric peak torque (PT) and isometric PT trials before (pretest) and after (posttest) performing 50 submaximal (65% of concentric PT), concentric, isokinetic (60°·s−1), forearm flexion muscle actions. Surface EMG and MMG signals were simultaneously recorded from the biceps brachii and brachioradialis muscles. Results: The results of the present study indicated similar decreases during both the concentric PT and isometric PT measurements for torque, EMG mean power frequency (MPF), and MMG MPF following the fatiguing workbout, but no changes in EMG amplitude (AMP) or MMG AMP. Conclusions: These findings suggest that decreases in torque as a result of fatiguing, dynamic muscle actions may have been due to the effects of metabolic byproducts on excitation–contraction coupling as indicated by the decreases in EMG MPF and MMG MPF, but lack of changes in EMG AMP and MMG AMP from both the biceps brachii and brachioradialis muscles.
      PubDate: 2016-09-30
      DOI: 10.3390/sports4040047
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 48: Comparıson of the Heart Rate and Blood Lactate
           Responses of Different Small Sided Games in Young Soccer Players

    • Authors: Yusuf Köklü, Utku Alemdaroğlu
      First page: 48
      Abstract: The purpose of this study was to compare the percentage of maximum heart rate (%HRmax), blood lactate (La−), and rating of perceived exertion (RPE, CR-10) responses across different formats of small-sided games (SSG) in elite young soccer players. Fourteen players (average age 16.7 ± 0.6 years; height 177.6 ± 4.1 cm; body mass 66.3 ± 4.7 kg; average training age 6.7 ± 1.6 years; percentage of body fat 8.4 ± 2.6%) volunteered to perform the YoYo intermittent recovery test (level 1) and eight bouts of soccer drills including 2-a-side, 3-a-side, and 4-a-side games without goalkeepers in random order at two-day intervals. Heart rates were monitored throughout the SSGs, whereas the RPE and venous blood lactate were determined at the end of the last bout of each SSG. The differences in La−, %HRmax, and RPE either across the different SSGs or between the bouts were identified using 3 × 8 (games × exercise bouts) two-way analysis of variance with repeated measures. Significant differences were found in terms of La−, RPE, and %HRmax among the different types of SSG (p ≤ 0.05). 3-a-side and 4-a-side games elicited significantly higher responses than 2-a-side games in terms of %HRmax (p ≤ 0.05), whereas 4-a-side games resulted in significantly lower La− and RPE responses compared to 2-a-side and 3-a-side games. The results of this study show that physiological responses differ according to the numbers of players involved in small-sided games. Therefore, it can be concluded that 3-a-side and 4-a-side games could be more effective in improving high intensity aerobic performance than 2-a-side games, which in turn are more appropriate for developing anaerobic performance.
      PubDate: 2016-09-29
      DOI: 10.3390/sports4040048
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 49: Effect of Carbohydrate Intake on Maximal Power
           Output and Cognitive Performances

    • Authors: Laura Pomportes, Jeanick Brisswalter, Arnaud Hays, Karen Davranche
      First page: 49
      Abstract: The present study aimed to assess the beneficial effect of acute carbohydrate (7% CHO) intake on muscular and cognitive performances. Seventeen high levels athletes in explosive sports (fencing and squash) participated in a randomized, double-blind study consisting in series of 6 sprints (5s) with a passive recovery (25s) followed by 15 min submaximal cycling after either maltodextrine and fructose (CHO) or placebo (Pl) intake. Cognitive performances were assessed before and after sprint exercise using a simple reaction time (SRT) task at rest, a visual scanning task (VS) and a Go/Nogo task (GNG) during a submaximal cycling exercise. Results showed a beneficial effect of exercise on VS task on both conditions (Pl: −283 ms; CHO: −423 ms) and on SRT only during CHO condition (−26 ms). In the CHO condition, SRT was faster after exercise whereas no effect of exercise was observed in the Pl condition. According to a qualitative statistical method, a most likely and likely positive effect of CHO was respectively observed on peak power (+4%) and tiredness (−23%) when compared to Pl. Furthermore, a very likely positive effect of CHO was observed on SRT (−8%) and a likely positive effect on visual scanning (−6%) and Go/Nogo tasks (−4%) without any change in accuracy. In conclusion acute ingestion of 250 mL of CHO, 60 min and 30 min before exercise, improve peak power output, decrease muscular tiredness and speed up information processing and visual detection without changing accuracy.
      PubDate: 2016-10-09
      DOI: 10.3390/sports4040049
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 50: Vegetarian, Gluten-Free, and Energy Restricted
           Diets in Female Athletes

    • Authors: Lynn Cialdella-Kam, Danielle Kulpins, Melinda Manore
      First page: 50
      Abstract: Female athletes who follow a diet that fails to meet energy and nutrient needs are at risk for musculoskeletal injuries, menstrual disturbances, and poor sports performance. Common nutritional concerns for the female athlete include low energy availability (EA) (i.e., energy intake from food remaining for metabolic processes after accounting for energy expended during exercise) and inadequate dietary intakes (i.e., not meeting sports nutrition guidelines) of carbohydrates, protein, essential fatty acids (EFAs), B-vitamins, calcium, iron, and vitamin D. Low EA and the associated nutrient deficiencies are more common in athletes who compete in weight-sensitive sports (i.e., aesthetic, gravitational, and weight category sports) because low body fat and mass confer a competitive advantage. Other athletes at risk for energy and nutrient deficits include athletes following a vegetarian or gluten-free diet (GFD). Careful dietary planning can help an athlete meet energy and nutrient needs. This review covers the nutrition issues associated with low EA and special diets (i.e., vegetarian and GFD) and describes strategies to help female athletes meet their energy and nutrient needs.
      PubDate: 2016-10-21
      DOI: 10.3390/sports4040050
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 51: Supplementation Strategies to Reduce Muscle
           Damage and Improve Recovery Following Exercise in Females: A Systematic

    • Authors: Jessica Köhne, Michael Ormsbee, Andrew McKune
      First page: 51
      Abstract: Exercise-induced muscle damage (EIMD) caused by unaccustomed or strenuous exercise can result in reduced muscle force, increased muscle soreness, increased intramuscular proteins in the blood, and reduced performance. Pre- and post-exercise optimal nutritional intake is important to assist with muscle-damage repair and reconditioning to allow for an accelerated recovery. The increased demand for training and competing on consecutive days has led to a variety of intervention strategies being used to reduce the negative effects of EIMD. Nutritional intervention strategies are largely tested on male participants, and few report on sex-related differences relating to the effects of the interventions employed. This review focuses on nutritional intervention strategies employed to negate the effects of EIMD, focussing solely on females.
      PubDate: 2016-11-11
      DOI: 10.3390/sports4040051
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 52: Relationship between Procedural Tactical
           Knowledge and Specific Motor Skills in Young Soccer Players

    • Authors: Rodrigo Aquino, Renato Marques, Grégory Petiot, Luiz Gonçalves, Camila Moraes, Paulo Santiago, Enrico Puggina
      First page: 52
      Abstract: The purpose of this study was to investigate the association between offensive tactical knowledge and the soccer-specific motor skills performance. Fifteen participants were submitted to two evaluation tests, one to assess their technical and tactical analysis. The motor skills performance was measured through four tests of technical soccer skills: ball control, shooting, passing and dribbling. The tactical performance was based on a tactical assessment system called FUT-SAT (Analyses of Procedural Tactical Knowledge in Soccer). Afterwards, technical and tactical evaluation scores were ranked with and without the use of the cluster method. A positive, weak correlation was perceived in both analyses (rho = 0.39, not significant p = 0.14 (with cluster analysis); and rho = 0.35; not significant p = 0.20 (without cluster analysis)). We can conclude that there was a weak association between the technical and the offensive tactical knowledge. This shows the need to reflect on the use of such tests to assess technical skills in team sports since they do not take into account the variability and unpredictability of game actions and disregard the inherent needs to assess such skill performance in the game.
      PubDate: 2016-11-17
      DOI: 10.3390/sports4040052
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 53: Goal Format in Small-Sided Soccer Games:
           Technical Actions and Offensive Scenarios of Prepubescent Players

    • Authors: Craig Pulling, Alex Twitchen, Carl Pettefer
      First page: 53
      Abstract: The aim of this study was to investigate the influence of the number of goal-posts and the positioning of goal-posts used within small-sided games on the frequency of technical actions and offensive scenarios performed by prepubescent players within soccer. The participants were eight male prepubescent soccer players (12.1 ± 0.5 years). The participants were video recorded for 20 min playing four different formats of 4v4 small-sided games: (1) standard two goal game; (2) four goal game, one goal in each corner; (3) two goal game with goal-posts positioned 9.14 m/10 yd infield, scoring only through the back of the goal; (4) four goal-game, one goal positioned 9.14 m/10 yd infield in each corner, scoring through either the front or back of each goal. Chi-squared tests of independence were utilized to statistically explore the impact of the different small-sided game formats. There were significant associations (p < 0.05) observed between the different small-sided game formats and the frequency of turns, dribbles, shots, goals and overlaps performed. For example, players performed more turns in small-sided game format two and more shots during small-sided game format four. It is suggested coaches should consider using a variation of the number and positioning of goal-posts in small-sided games as an effective training tool in the development of prepubescent soccer players. This will enable coaches to vary the focus of sessions, and develop specific technical and tactical actions within a situation similar to that of real match-play.
      PubDate: 2016-11-25
      DOI: 10.3390/sports4040053
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 54: Identification of Defensive Performance Factors
           in the 2010 FIFA World Cup South Africa

    • Authors: Claudio Casal, Miguel Andujar, José Losada, Toni Ardá, Rubén Maneiro
      First page: 54
      Abstract: The aim of this study was to determine the efficacy of defensive play in elite football, to identify variables associated with the direct recovery of ball possession, and to propose a model for predicting the success of defensive transitions. We analyzed 804 transitions in the final stages of the Fedération Internationale Football Association (FIFA) World Cup 2010, and investigated the following variables using univariate, bivariate, and multivariate analyses: duration of defensive transition, possession loss zone, position of players at the start and end of the defensive transitions, defensive organization, general defensive approach, time of the match, position of defense, zone in which the offensive transition ends, match status, and outcome of the defensive transition. We found that the defensive transitions started most frequently in the middle offensive zone (48.9%), with an organized defense set-up (98.8%), and were unsuccessful on 57.2% of occasions. The bivariate analysis showed that the variable most strongly associated with direct recovery of the possession of the ball (p = 0.018) is the area in which the ball is lost, and the multivariate analysis showed that the duration of the defensive transition can be used as a performance indicator, with transitions lasting between 0 and 15 s associated with a higher likelihood of directly recovering the ball. This work has allowed us to identify a pattern of tactical-strategic behavior with major probabilities of success in the defensive transitions. These results will be able to be used by coaches to improve the performance of their teams in this type of situation in the game.
      PubDate: 2016-11-30
      DOI: 10.3390/sports4040054
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 55: A Three-Dimensional Movement Analysis of the
           Spike in Fistball

    • Authors: Andreas Bund, Saeed Ghorbani, Franziska Rathjens
      First page: 55
      Abstract: Due to its relevancy to point scoring, the spike is considered as one of the most important skills in fistball. Biomechanical analyses of this sport are very rare. In the present study, we performed a three-dimensional kinematic analysis of the fistball spike, which helps to specify performance parameters on a descriptive level. Recorded by four synchronized cameras (120 Hz) and linked to the motion capture software Simi Motion® 5.0, three female fistball players of the second German league (24–26 years, 1.63–1.69 m) performed several spikes under standardized conditions. Results show that the segment velocities of the arm reached their maximum successively from proximal to distal, following the principle of temporal coordination of single impulses. The wrist shows maximum speed when the fist hits the ball. The elbow joint angle performs a rapid transition from a strong flexion to a (almost) full extension; however, the extension is completed after the moment of ball impact. In contrast, the shoulder joint angle increases almost linearly until the fistball contact and decreases afterward. The findings can be used to optimize the training of the spike.
      PubDate: 2016-12-02
      DOI: 10.3390/sports4040055
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 56: Relationships and Predictive Capabilities of
           Jump Assessments to Soccer-Specific Field Test Performance in Division I
           Collegiate Players

    • Authors: Robert Lockie, Alyssa Stage, John Stokes, Ashley Orjalo, DeShaun Davis, Dominic Giuliano, Matthew Moreno, Fabrice Risso, Adrina Lazar, Samantha Birmingham-Babauta, Tricia Tomita
      First page: 56
      Abstract: Leg power is an important characteristic for soccer, and jump tests can measure this capacity. Limited research has analyzed relationships between jumping and soccer-specific field test performance in collegiate male players. Nineteen Division I players completed tests of: leg power (vertical jump (VJ), standing broad jump (SBJ), left- and right-leg triple hop (TH)); linear (30 m sprint; 0–5 m, 5–10 m, 0–10, 0–30 m intervals) and change-of-direction (505) speed; soccer-specific fitness (Yo-Yo Intermittent Recovery Test Level 2); and 7 × 30-m sprints to measure repeated-sprint ability (RSA; total time (TT), performance decrement (PD)). Pearson’s correlations (r) determined jump and field test relationships; stepwise regression ascertained jump predictors of the tests (p < 0.05). All jumps correlated with the 0–5, 0–10, and 0–30 m sprint intervals (r = −0.65–−0.90). VJ, SBJ, and left- and right-leg TH correlated with RSA TT (r = −0.51–−0.59). Right-leg TH predicted the 0–5 and 0–10 m intervals (R2 = 0.55–0.81); the VJ predicted the 0–30 m interval and RSA TT (R2 = 0.41–0.84). Between-leg TH asymmetry correlated with and predicted left-leg 505 and RSA PD (r = −0.68–0.62; R2 = 0.39–0.46). Improvements in jumping ability could contribute to faster speed and RSA performance in collegiate soccer players.
      PubDate: 2016-12-03
      DOI: 10.3390/sports4040056
      Issue No: Vol. 4, No. 4 (2016)
  • Sports, Vol. 4, Pages 36: Differences in Spatial Physical Activity
           Patterns between Weekdays and Weekends in Primary School Children: A
           Cross-Sectional Study Using Accelerometry and Global Positioning System

    • Authors: Rahel Bürgi, Eling de Bruin
      First page: 36
      Abstract: Targeting the weekend to promote physical activity (PA) in children seems to be promising given that they tend to be less physically active and, particularly, as the age-related decline in PA is more marked during weekends. Considering the ambiguity of why children are not able to maintain their PA level on weekends, the aim of the present study was to objectively investigate differences in children’s spatial PA patterns between week and weekend days using the combination of Global Positioning System (GPS) and accelerometry. Seventy-four second graders (aged 7–9 years) and 98 sixth graders (aged 11–14 years) wore an accelerometer and GPS sensor for seven consecutive days to determine where children spend time and engage in PA. Time-matched accelerometer and GPS data was mapped with a geographic information system and multilevel analyses accounting for the hierarchical structure of the data were conducted. Differences between weekdays and weekends regarding the total time spent and the absolute and relative level of PA in various settings were found in both age groups. The findings support previous research pointing to the importance of targeting weekend PA, especially when children grow older. Future interventions should encourage children to use outdoor spaces more frequently on weekends, rather than stay at home, and to commute actively to destinations other than school.
      PubDate: 2016-06-27
      DOI: 10.3390/sports4030036
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 37: America’s Cup Sailing: Effect of Standing
           Arm-Cranking (“Grinding”) Direction on Muscle Activity, Kinematics,
           and Torque Application

    • Authors: Simon Pearson, Patria Hume, John Cronin, David Slyfield
      First page: 37
      Abstract: Grinding is a key physical element in America’s Cup sailing. This study aimed to describe kinematics and muscle activation patterns in relation to torque applied in forward and backward grinding. Ten male America’s Cup sailors (33.6 ± 5.7 years, 97.9 ± 13.4 kg, 186.6 ± 7.4 cm) completed forward and backward grinding on a customised grinding ergometer. In forward grinding peak torque (77 Nm) occurred at 95° (0° = crank vertically up) on the downward section of the rotation at the end of shoulder flexion and elbow extension. Backward grinding torque peaked at 35° (69 Nm) following the pull action (shoulder extension, elbow flexion) across the top of the rotation. During forward grinding, relatively high levels of torque (>50 Nm) were maintained through the majority (72%) of the cycle, compared to 47% for backward grinding, with sections of low torque corresponding with low numbers of active muscles. Variation in torque was negatively associated with forward grinding performance (r = −0.60; 90% CI −0.88 to −0.02), but positively associated with backward performance (r = 0.48; CI = −0.15 to 0.83). Magnitude and distribution of torque generation differed according to grinding direction and presents an argument for divergent training methods to improve forward and backward grinding performance.
      PubDate: 2016-06-27
      DOI: 10.3390/sports4030037
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 38: Effects of Intermittent Neck Cooling During
           Repeated Bouts of High-Intensity Exercise

    • Authors: Andrew Galpin, James Bagley, Blake Whitcomb, Leonard Wiersma, Jakob Rosengarten, Jared Coburn, Daniel Judelson
      First page: 38
      Abstract: The purpose of this investigation was to determine the influence of intermittent neck cooling during exercise bouts designed to mimic combat sport competitions. Participants (n = 13, age = 25.3 ± 5.0 year height = 176.9 ± 7.5 cm, mass = 79.3 ± 9.0 kg, body fat = 11.8% ± 3.1%) performed three trials on a cycle ergometer. Each trial consisted of two, 5-min high-intensity exercise (HEX) intervals (HEX1 and HEX2—20 s at 50% peak power, followed by 15 s of rest), and a time to exhaustion (TTE) test. One-minute rest intervals were given between each round (RI1 and RI2), during which researchers treated the participant’s posterior neck with either (1) wet-ice (ICE); (2) menthol spray (SPRAY); or (3) no treatment (CON). Neck (TNECK) and chest (TCHEST) skin temperatures were significantly lower following RI1 with ICE (vs. SPRAY). Thermal sensation decreased with ICE compared to CON following RI1, RI2, TTE, and a 2-min recovery. Rating of perceived exertion was also lower with ICE following HEX2 (vs. CON) and after RI2 (vs. SPRAY). Treatment did not influence TTE (68.9 ± 18.9s). The ability of intermittent ICE to attenuate neck and chest skin temperature rises during the initial HEX stages likely explains why participants felt cooler and less exerted during equivalent HEX bouts. These data suggest intermittent ICE improves perceptual stress during short, repeated bouts of vigorous exercise.
      PubDate: 2016-06-29
      DOI: 10.3390/sports4030038
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 39: The Effect of Recovery Duration on Technical
           Proficiency during Small Sided Games of Football

    • Authors: Scott McLean, Hugo Kerhervé, Mitchell Naughton, Geoff Lovell, Adam Gorman, Colin Solomon
      First page: 39
      Abstract: The aim of this study was to determine the effect of increasing the duration of the recovery periods separating serial bouts of small sided games (SSG) of football on technical skills (TS). Twelve semi-professional footballers (mean ± SD; age 21 ± 3 years; VO2peak 64 ± 7 mL∙min∙kg−1; playing experience 15 ± 3 years) completed two SSG sessions, consisting of 3 vs. 3 players and 6 bouts of 2 min, separated by either 30 s recovery (REC-30) or 120 s recovery (REC-120). Sixteen TS, including passing, possession, and defensive related variables, and exercise intensity (heart rate, rating of perceived exertion, time motion descriptors) during the bouts were measured. Repeated measures ANOVA were used to determine differences between-conditions, for TS. The number of successful tackles was significantly higher, and the average time each team maintained possession was significantly lower in REC-120 compared to REC-30. There were no significant differences for all other TS variables, or exercise intensity measures between REC-30 and REC-120. Overall, a four-fold increase in the duration of recovery separating SSG bouts did not alter the technical skill execution of players. The experience and skill level of the players, combined with an apparent regulation of effort through pacing, may have assisted in the maintenance of technical skill execution.
      PubDate: 2016-07-08
      DOI: 10.3390/sports4030039
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 40: Betalain-Rich Concentrate Supplementation
           Improves Exercise Performance in Competitive Runners

    • Authors: Justin Van Hoorebeke, Casey Trias, Brian Davis, Christina Lozada, Gretchen Casazza
      First page: 40
      Abstract: This study aimed to determine the effects of a betalain-rich concentrate (BRC) of red beets, containing antioxidant and anti-inflammatory properties, on performance and exercise-related muscle damage. Thirteen (25.3 ± 5.4 years) competitive male runners completed two double-blind, cross-over, randomized trials (BRC and control) separated by seven days. Each trial was preceded by six days of supplementation with 100 mg of BRC or control. On the seventh day, exercise trials commenced 150 min after supplementation with 50 mg BRC or control and consisted of 30 min of treadmill running (77 ± 4% VO2max) followed by a 5-km time trial (TT). During exercise at the same intensity, BRC resulted in a 3% lower heart rate, a 15% lower rate of perceived exertion (RPE) and a 14% lower blood lactate concentration compared to the control (p = 0.05). Five-kilometer TT duration (23.0 ± 4.2 versus 23.6 ± 4.0 min) was faster in 10 of the 13 subjects, and RPE was lower (p < 0.05) with the BRC treatment compared to the control. Lactate dehydrogenase, a marker of muscle damage, increased less from baseline to immediately and 30 min after the 5-km TT with the BRC treatment, despite no differences in subjective measures of muscle soreness and fatigue. In summary, BRC supplementation improved 5-km performance time in male competitive runners.
      PubDate: 2016-07-25
      DOI: 10.3390/sports4030040
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 41: Profiling of Junior College Football Players and
           Differences between Position Groups

    • Authors: Robert Lockie, Adrina Lazar, Ashley Orjalo, DeShaun Davis, Matthew Moreno, Fabrice Risso, Matthew Hank, Randal Stone, Nicholas Mosich
      First page: 41
      Abstract: This study profiled junior college football players. Sixty-two subjects completed vertical jump (VJ; height and peak power), standing broad jump (SBJ), 36.58 m sprint, pro-agility shuttle, three-cone drill, and maximal-repetition bench press and front squat. The sample included 2 quarterbacks (QB), 7 running backs (RB), 13 wide receivers (WR), 1 tight end (TE), 18 defensive backs (DB), 8 linebackers (LB), and 13 offensive and defensive linemen (LM). To investigate positional differences, subjects were split into skill (SK; WR, DB), big skill (BSK; QB, RB, TE, LB), and LM groups. A one-way ANOVA determined between-group differences. LM were taller and heavier than SK and BSK players. The SK and BSK groups were faster than LM in the 0–36.58 m sprint, pro-agility shuttle, and three-cone drill (p ≤ 0.009). The SK group had greater VJ height and SBJ distance; LM generated greater VJ peak power (p ≤ 0.022). There were no between-group differences in the strength endurance tests. Compared to Division I data, junior college players were smaller, slower, and performed worse in jump tests. Positional differences in junior college football are typical to that of established research. Junior college players should attempt to increase body mass, and improve speed and lower-body power.
      PubDate: 2016-08-05
      DOI: 10.3390/sports4030041
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 42: Beneficial Effects of New Zealand Blackcurrant
           Extract on Maximal Sprint Speed during the Loughborough Intermittent
           Shuttle Test

    • Authors: Mark Willems, Luke Cousins, David Williams, Sam Blacker
      First page: 42
      Abstract: New Zealand blackcurrant (NZBC) extract has been shown to enhance high-intensity intermittent treadmill running. We examined the effects of NZBC extract during the Loughborough Intermittent Shuttle Test (LIST) which involves 5 × 15 min blocks with intermittent 15-m maximal sprints, interspersed by moderate and high-intensity running to simulate team sport activity, and a subsequent run to exhaustion. Thirteen males (age: 22 ± 1 year, V ˙ O 2 max : 50 ± 5 mL·kg−1·min−1) participated in three indoor sessions (T: 24 ± 3 °C, humidity: 52% ± 9%). In the first session, a multistage fitness test was completed to determine peak running speed and estimate V ˙ O 2 max . Participants consumed NZBC extract in capsules (300 mg·day−1 CurraNZ™) or placebo (PL) (300 mg·day−1 microcrystalline cellulose M102) for seven days in a double-blind, randomized, cross-over design (wash-out at least seven days). NZBC extract did not affect average 15-m sprint times in each block. NZBC reduced slowing of the fastest sprint between block 1 and 5 (PL: 0.12 ± 0.07 s; NZBC: 0.06 ± 0.12 s; p < 0.05). NZBC extract had no effect on heart rate, vertical jump power, lactate and time to exhaustion (PL: 13.44 ± 8.09 min, NZBC: 15.78 ± 9.40 min, p > 0.05). However, eight participants had higher running times to exhaustion when consuming NZBC extract. New Zealand blackcurrant extract may enhance performance in team sports with repeated maximal sprints.
      PubDate: 2016-08-05
      DOI: 10.3390/sports4030042
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 43: Greater Strength Drives Difference in Power
           between Sexes in the Conventional Deadlift Exercise

    • Authors: Margaret Jones, Andrew Jagim, G. Haff, Patrick Carr, Joel Martin, Jonathan Oliver
      First page: 43
      Abstract: Limited research exists comparing sex differences in muscular power. The primary purpose of this research was to determine if differences exist in power and velocity in the conventional deadlift (CDL). A secondary purpose was to examine the relationship among power, velocity, strength, and fat free mass (FFM). Eighteen strength trained athletes with ≥1 year CDL experience (women: n = 9, 29 ± 2 years, 162.3 ± 1.8 cm, 62 ± 2.4 kg, 23.3 ± 3.2 % body fat (%BF); men: n = 9, 29 ± 3 years, 175.6 ± 1.8 cm, 85.5 ± 1.4 kg, 14.8 ± 2.4 %BF), and ≥1.5 one repetition maximum (1-RM) CDL: body mass (BM) ratio (women: 1.6 ± 0.1 1-RM CDL: BM; men: 2.3 ± 0.1 1-RM CDL: BM), performed baseline (body composition, 1-RM CDL) and experimental sessions, in which velocity and power were measured at 30%, 60%, and 90% 1-RM. Repeated measures ANOVA and bivariate correlations were conducted. Men produced higher absolute average and peak power across all loads, but higher average velocity at only 30% 1-RM. When normalized to FFM, men produced higher peak and average power; however, women produced higher peak and average velocities across all loads. FFM and 1-RM were correlated with power. Greater power observed in men is driven by larger muscle mass, which contributes to greater strength.
      PubDate: 2016-08-05
      DOI: 10.3390/sports4030043
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 44: Star Excursion Balance Test in Young Athletes
           with Back Pain

    • Authors: Edem Appiah-Dwomoh, Steffen Müller, Miralem Hadzic, Frank Mayer
      First page: 44
      Abstract: The Star Excursion Balance Test (SEBT) is effective in measuring dynamic postural control (DPC). This research aimed to determine whether DPC measured by the SEBT in young athletes (YA) with back pain (BP) is different from those without BP (NBP). 53 BP YA and 53 NBP YA matched for age, height, weight, training years, training sessions/week and training minutes/session were studied. Participants performed 4 practice trials after which 3 measurements in the anterior, posteromedial and posterolateral SEBT reach directions were recorded. Normalized reach distance was analyzed using the mean of all 3 measurements. There was no statistical significant difference (p > 0.05) between the reach distance of BP (87.2 ± 5.3, 82.4 ± 8.2, 78.7 ± 8.1) and NBP (87.8 ± 5.6, 82.4 ± 8.0, 80.0 ± 8.8) in the anterior, posteromedial and posterolateral directions respectively. DPC in YA with BP, as assessed by the SEBT, was not different from NBP YA.
      PubDate: 2016-08-23
      DOI: 10.3390/sports4030044
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 45: Coffee and Caffeine Ingestion Have Little Effect
           on Repeated Sprint Cycling in Relatively Untrained Males

    • Authors: Neil Clarke, Harry Baxter, Emmanuel Fajemilua, Victoria Jones, Samuel Oxford, Darren Richardson, Charlotte Wyatt, Peter Mundy
      First page: 45
      Abstract: The present study investigated the effect of ingesting caffeine-dose-matched anhydrous caffeine or coffee on the performance of repeated sprints. Twelve recreationally active males (mean ± SD age: 22 ± 2 years, height: 1.78 ± 0.07 m, body mass: 81 ± 16 kg) completed eighteen 4 s sprints with 116 s recovery on a cycle ergometer on four separate occasions in a double-blind, randomised, counterbalanced crossover design. Participants ingested either 3 mg·kg−1 of caffeine (CAF), 0.09 g·kg−1 coffee, which provided 3 mg·kg−1 of caffeine (COF), a taste-matched placebo beverage (PLA), or a control condition (CON) 45 min prior to commencing the exercise protocol. Peak and mean power output and rating of perceived exertion (RPE) were recorded for each sprint. There were no significant differences in peak power output (CAF: 949 ± 199 W, COF: 949 ± 174 W, PLA: 971 ± 149 W and CON: 975 ± 170 W; p = 0.872; η P 2 = 0.02) or mean power output (CAF: 873 ± 172 W, COF: 862 ± 44 W, PLA: 887 ± 119 W and CON: 892 ± 143 W; p = 0.819; η P 2 = 0.03) between experimental conditions. Mean RPE was similar for all trials (CAF: 11 ± 2, COF: 11 ± 2, PLA: 11 ± 2 and CON: 11 ± 2; p = 0.927; η P 2 = 0.01). Neither the ingestion of COF or CAF improved repeated sprint cycling performance in relatively untrained males.
      PubDate: 2016-08-29
      DOI: 10.3390/sports4030045
      Issue No: Vol. 4, No. 3 (2016)
  • Sports, Vol. 4, Pages 21: The Influence of Various Distraction Stimuli on
           Affective Responses during Recumbent Cycle Ergometry

    • Authors: Paul Miller, Eric Hall, Elizabeth Bailey
      First page: 21
      Abstract: (1) Background: Acute bouts of exercise have been associated with affective changes. Exercise supplemented with distraction may divert attention from unpleasant feelings commonly associated with exercise to more pleasant feelings. The purpose of this study was to compare affective responses to exercise with and without distraction. (2) Methods: 25 individuals volunteered for this investigation and completed all three conditions. This study included three 30 min cycle ergometry exercise conditions, a control condition with no stimuli and two test conditions; one supplemented with a self-selected video and the other self-selected music. The Feeling Scale (FS) was administered prior to, every 10 min during, immediately following, and 10 min post exercise. (3) Results: These data demonstrate a significant condition effect for FS during exercise. The condition effect was due to FS being greater in the video and distraction conditions. There was no time by condition interaction seen during exercise. (4) Conclusion: These data indicate that distraction may be effective in supporting a more pleasant exercise experience and could potentially increase exercise adherence.
      PubDate: 2016-03-23
      DOI: 10.3390/sports4020021
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 22: The Acute Effects of Heavy Deadlifts on Vertical
           Jump Performance in Men

    • Authors: Jerry Arias, Jared Coburn, Lee Brown, Andrew Galpin
      First page: 22
      Abstract: The purpose of this study was to investigate the effects of deadlifts as a postactivation potentiation stimulus on vertical jump performance. Fifteen men (age, 23.9 ± 4.2 years; height, 176.3 ± 8.6 cm; mass, 76.1 ± 16.3 kg) participated in the study. Participants visited the lab for three sessions, each separated by at least 48 h. One repetition maximum (1RM) in the deadlift was measured during the first visit. For Visit 2, participants performed one of two experimental sessions: a deadlift session or a control session. Participants performed a single maximal vertical jump (VJ; counter movement jump without an arm swing), then either performed five repetitions of the deadlift using 85% 1RM (deadlift session) or were told to stand still for ten seconds (control). Following either condition, participants performed single VJ at 15 s, 2, 4, 6, 8, 10, 12, 14, and 16 min post condition. Peak VJ height and peak ground reaction forces (pGRF) were measured using a force plate. For Visit 3, whatever condition was not administered at Visit 2 was performed. The results showed that VJ height was significantly lower 15 s following deadlifting (36.9 ± 5.1 cm) compared to the control condition (40.1 ± 4.6 cm). In addition, VJ height 15 s after the deadlift was lower than VJ height measured at minutes 2–16 following the deadlift. Performance of five repetitions of deadlifting did not affect pGRF. These results suggest that performing five repetitions of the deadlift exercise at 85% 1RM does not induce a postactivation potentiation (PAP) effect, and may in fact cause an acute reduction in VJ performance.
      PubDate: 2016-03-23
      DOI: 10.3390/sports4020022
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 23: The Effects of Mental Imagery with
           Video-Modeling on Self-Efficacy and Maximal Front Squat Ability

    • Authors: Daniel Buck, Jasmin Hutchinson, Christa Winter, Brian Thompson
      First page: 23
      Abstract: This study was designed to assess the effectiveness of mental imagery supplemented with video-modeling on self-efficacy and front squat strength (three repetition maximum; 3RM). Subjects (13 male, 7 female) who had at least 6 months of front squat experience were assigned to either an experimental (n = 10) or a control (n = 10) group. Subjects′ 3RM and self-efficacy for the 3RM were measured at baseline. Following this, subjects in the experimental group followed a structured imagery protocol, incorporating video recordings of both their own 3RM performance and a model lifter with excellent technique, twice a day for three days. Subjects in the control group spent the same amount of time viewing a placebo video. Following three days with no physical training, measurements of front squat 3RM and self-efficacy for the 3RM were repeated. Subjects in the experimental group increased in self-efficacy following the intervention, and showed greater 3RM improvement than those in the control group. Self-efficacy was found to significantly mediate the relationship between imagery and front squat 3RM. These findings point to the importance of mental skills training for the enhancement of self-efficacy and front squat performance.
      PubDate: 2016-04-14
      DOI: 10.3390/sports4020023
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 24: Radiographic Assessment of Anatomic Risk Factors
           Associated with Acute, Lateral Patellar Dislocation in the Immature Knee

    • Authors: Thai Trinh, Andrew Mundy, Matthew Beran, Kevin Klingele
      First page: 24
      Abstract: Acute patellar dislocation remains a common injury in both adult and pediatric patients. Non-operative management has been advocated for patients without a history of recurrent instability. Although pathologic thresholds for consideration of operative management have previously been reported in adults, it is largely unknown in children. A retrospective review of all skeletally immature patients diagnosed with acute lateral patellar dislocation who had MRI imaging were included for analysis. An age-based control group was also identified. Six radiographic measurements were compared: lateral trochlear inclination (LTI), trochlear facet asymmetry (TFA), trochlear depth (TD), tibial tuberosity–trochlear groove (TT–TG), sulcus angle (SA) and patellar height ratio. A total of 178 patients were included for analysis (study: n = 108, control: n = 70). The mean age of patients in the study and control groups was 13.7 and 12.1 years respectively (p ≤ 0.001). Study group patients had significant differences in all radiographic measurements including a decreased LTI (p < 0.001), increased TFA (p < 0.001) and SA (p < 0.001). The mean trochlear depth was 3.4 mm and 5.6 mm for patients in the study and control groups respectively (p < 0.001). Study group patients had an increased patellar height ratio (p < 0.001) and TT–TG distance (p < 0.001). Morphologic abnormalities may predispose skeletally immature patients to an increased risk of acute lateral patellar instability.
      PubDate: 2016-04-15
      DOI: 10.3390/sports4020024
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 25: Autonomy Mediates the Relationship between
           Personality and Physical Activity: An Application of Self-Determination

    • Authors: Meredith Ramsey, Eric Hall
      First page: 25
      Abstract: This study sought to examine tenets of Self-Determination Theory by testing a mediation model of physical activity and personality via autonomy. A total of 290 adults were recruited to complete a one-time online survey of exercise habits and individual characteristics. Surveys assessed personality, autonomy, and physical activity. A measurement model specifying direct effects between personality dimensions and physical activity and indirect effects operating through autonomy provided an excellent fit to the data (Χ2 = 0.66, df = 3, p = 0.88, RMSEA(90% CI) = 0.00 (0.00–0.05), CFI = 0.99, SRMR = 0.01). Results indicated significant (p < 0.05) effects of Extroversion (β = 0.42), Conscientiousness (β = 0.96), and Emotional Stability (β = 0.60) on autonomy, which in turn, was significantly associated with physical activity (β = 0.55). No significant effects were observed for Agreeableness or Intellect. None of the personality constructs were found to be directly associated with physical activity. This model accounted for 27% of the variance in physical activity. The results of this study suggest that autonomy is significantly associated with physical activity. Therefore, attempts to improve autonomy in individuals may be a useful intervention strategy in improving physical activity levels.
      PubDate: 2016-04-29
      DOI: 10.3390/sports4020025
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 26: The Effects of a Multi-Ingredient Performance
           Supplement on Hormonal Profiles and Body Composition in Male College

    • Authors: Matthew Sharp, Kevin Shields, Jacob Rauch, Ryan Lowery, Shane Durkee, Gabriel Wilson, Eduardo De Souza
      First page: 26
      Abstract: Periods of intense training can elicit an acute decline in performance and body composition associated with weakened hormone profiles. This study investigated the effects of a multi-ingredient performance supplement (MIPS) on body composition and hormone levels in college athletes following a six-week training protocol. Twenty male college athletes were equally assigned to MIPS and placebo (PLA) groups for supplementation (three pills, twice daily) in conjunction with resistance training and specialized sports training (e.g., nine total sessions/week) for six weeks. Dual Energy X-ray Absorptiometry determined body composition at weeks 0 and 6. Serum samples collected at weeks 0 and 6 determined free testosterone (FT), total testosterone (TT), IGF-1 and total estrogen (TE) levels. PLA experienced a significant decline in lean body mass (LBM) (−1.5 kg; p < 0.05) whereas the MIPS sustained LBM. The MIPS increased TT 21.9% (541.5 ± 48.7 to 639.1 ± 31.7) and increased FT 15.2% (13.28 ± 1.1 to 15.45 ± 1.3 ng/dL) (p < 0.05). Conversely, PLA decreased TT 7.9% (554.5 ± 43.3 to 497.2 ± 39.1 ng/dL), decreased FT 17.4% (13.41 ± 1.8 to 11.23 ± 2.55 ng/dL), and decreased FT:E 12.06% (p < 0.05). These findings suggest the MIPS can prevent decrements in LBM and anabolic hormone profiles during intense training periods.
      PubDate: 2016-05-06
      DOI: 10.3390/sports4020026
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 27: Optimal Timing for Post-Activation Potentiation
           in Women Collegiate Volleyball Players

    • Authors: Robert Ah Sue, Kent Adams, Mark DeBeliso
      First page: 27
      Abstract: Post-activation potentiation (PAP) has been shown to acutely amplify muscular power output and may be advantageous for athletes looking to improve performance. PAP may have an acute window of effectiveness between 2 to 20 min. With correct timing and implementation it may be possible to induce PAP in competitive situations. The purpose of this study was to examine the time frame of potentiation following a PAP warm-up in collegiate female volleyball players. In this study, nine female collegiate volleyball players completed three laboratory sessions over the course of 10 days. During the first session, the athlete’s 5-RM back squat was determined for subsequent use as the conditioning activity to initiate PAP. A repeated measures experimental design was then employed for Sessions 2 and 3 where half of the participants alternately performed either a dynamic or PAP warm-up prior to performing a standing long jump (SLJ) at 2, 6, 10, 14, and 18 min. A mixed-factor repeated measures ANOVA was used to determine the effects of the two warm-up strategies (PAP vs. dynamic) on standing long jump (SLJ) performance across time. There was a significant effect for time (p < 0.01) and warm-up strategy (p < 0.01). Bonferroni post hoc techniques determined that the SLJs that followed the PAP warm-up were significantly greater at 2 (4.8%), 6 (3.6%), and 10 (3.6%) min compared to SLJs post-dynamic warm-up (p < 0.05). However, those differences did not persist at 14 or 18 min (p > 0.05). Further analysis included non-parametric pairwise comparisons (Wilcoxon signed-rank tests) between the SLJ scores at 2, 6, 10, 14, and 18 min (PAP vs. dynamic). The non-parametric results were consistent with the parametric results. Within the parameters of this study, it is concluded that performing a 5-RM back squat induces a measureable PAP effect for up to 10 min.
      PubDate: 2016-05-06
      DOI: 10.3390/sports4020027
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 28: Martial Arts and Metabolic Diseases

    • Authors: Hidetaka Hamasaki
      First page: 28
      Abstract: Different forms of martial arts are practiced worldwide, each with various intensities of physical activity. These disciplines are potentially an effective exercise therapy for metabolic diseases. Tai chi is the most well-studied style of martial arts and has shown evidence of its effect on metabolic diseases; however, little evidence is available regarding the association between other styles of martial arts and metabolic health. To summarize and evaluate the effects of martial arts on metabolic diseases, eligible articles were searched by using Pubmed. To date, systematic reviews provide no definite conclusion on the effectiveness of tai chi for treating metabolic diseases because of a small numbers of subjects, short durations of clinical trials, and some biases involved in testing. However, there are several clinical studies on subjects with metabolic diseases, which show that tai chi improves obesity, glycemic control, blood pressure control, and lipid profiles. Currently, some limited evidence suggests that other martial arts, such as kung fu and karate, may be beneficial for body composition, glycemic control, and arterial stiffness. To clarify the effectiveness of martial arts for treating metabolic diseases, well-designed prospective studies, preferably with a larger number of subjects and of longer duration, are warranted.
      PubDate: 2016-05-09
      DOI: 10.3390/sports4020028
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 29: Improvement in 100-m Sprint Performance at an
           Altitude of 2250 m

    • Authors: Nicholas Linthorne
      First page: 29
      Abstract: A fair system of recognizing records in athletics should consider the influence of environmental conditions on performance. The aim of this study was to determine the effect of an altitude of 2250 m on the time for a 100-m sprint. Competition results from the 13 Olympic Games between 1964 and 2012 were corrected for the effects of wind and de-trended for the historical improvement in performance. The time advantage due to competing at an altitude of 2250 m was calculated from the difference between the mean race time at the 1968 Olympic Games in Mexico City and the mean race times at the low-altitude competition venues. The observed time advantage of Mexico City was 0.19 (±0.02) s for men and 0.21 (±0.05) s for women (±90% confidence interval). These results indicate that 100-m sprinters derive a substantial performance advantage when competing at a high-altitude venue and that an altitude of 1000 m provides an advantage equivalent to a 2 m/s assisting wind (0.10 s). Therefore, the altitude of the competition venue as well as the wind speed during the race should be considered when recognizing record performances.
      PubDate: 2016-05-12
      DOI: 10.3390/sports4020029
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 30: Reliability and Validity of the Early Years
           Physical Activity Questionnaire (EY-PAQ)

    • Authors: Daniel Bingham, Paul Collings, Stacy Clemes, Silvia Costa, Gillian Santorelli, Paula Griffiths, Sally Barber
      First page: 30
      Abstract: Measuring physical activity (PA) and sedentary time (ST) in young children (<5 years) is complex. Objective measures have high validity but require specialist expertise, are expensive, and can be burdensome for participants. A proxy-report instrument for young children that accurately measures PA and ST is needed. The aim of this study was to assess the reliability and validity of the Early Years Physical Activity Questionnaire (EY-PAQ). In a setting where English and Urdu are the predominant languages spoken by parents of young children, a sample of 196 parents and their young children (mean age 3.2 ± 0.8 years) from Bradford, UK took part in the study. A total of 156 (79.6%) questionnaires were completed in English and 40 (20.4%) were completed in transliterated Urdu. A total of 109 parents took part in the reliability aspect of the study, which involved completion of the EY-PAQ on two occasions (7.2 days apart; standard deviation (SD) = 1.1). All 196 participants took part in the validity aspect which involved comparison of EY-PAQ scores against accelerometry. Validty anaylsis used all data and data falling with specific MVPA and ST boundaries. Reliability was assessed using intra-class correlations (ICC) and validity by Bland–Altman plots and rank correlation coefficients. The test re-test reliability of the EY-PAQ was moderate for ST (ICC = 0.47) and fair for moderate-to-vigorous physical activity (MVPA)(ICC = 0.35). The EY-PAQ had poor agreement with accelerometer-determined ST (mean difference = −87.5 min·day−1) and good agreement for MVPA (mean difference = 7.1 min·day−1) limits of agreement were wide for all variables. The rank correlation coefficient was non-significant for ST (rho = 0.19) and significant for MVPA (rho = 0.30). The EY-PAQ has comparable validity and reliability to other PA self-report tools and is a promising population-based measure of young children’s habitual MVPA but not ST. In situations when objective methods are not possible for measurement of young children’s MVPA, the EY-PAQ may be a suitable alternative but only if boundaries are applied.
      PubDate: 2016-05-26
      DOI: 10.3390/sports4020030
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 31: Heart Rate Responses during Small Sided Games
           and Official Match-Play in Soccer

    • Authors: Alper Aşçı
      First page: 31
      Abstract: Small sided games (SSGs) are a match specific type of training. In addition, there is an insufficient number of studies that compare heart rate (HR) responses of SSGs and official match-play (OM). The purpose of this study was to investigate the heart rate responses during SSGs and OM in young soccer players. Twenty-two male soccer players (mean ± SD; age 17.4 ± 0.9 years, height 174.9 ± 6.6 cm, body weight 67.7 ± 8.1 kg) volunteered to participate in this study. The first session included anthropometric measurements and a maximum running test (RT). Following the RT session, all players participated in five different randomly ordered SSG sessions (3-, 4-, 5-, 7- and 9-a-side with goalkeepers). OMs were also monitored in the fourth week of the study. A one-way multivariate repeated-measures analysis of variance (MANOVA) was then conducted to evaluate the differences between the SSGs and OM. The results showed that 3-a-side elicited significantly higher HR and %HRmax than other SSGs and OM, whereas 9-a-side resulted in significantly lower HR and %HRmax compared to other SSG formats and OM (p < 0.05). In conclusion, 3-a-side, 4-a-side and 5-a-side SSG formats provide players with the opportunity to spend sufficient proportion of time spent in high intensity zones that are specific to match demands.
      PubDate: 2016-05-30
      DOI: 10.3390/sports4020031
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 32: The Effects of Exercise on Natriuretic Peptides
           in Individuals without Heart Failure

    • Authors: Hidetaka Hamasaki
      First page: 32
      Abstract: Cardiac natriuretic peptides (NPs) play an important role in the regulation of energy expenditure in skeletal muscle and adipose tissue. A systematic review on the effects of exercise on NPs in patients with heart failure reported that aerobic and resistance training reduced NPs; however, the effects of exercise on NPs and the underlying mechanism of exercise-induced NP secretion in subjects without heart failure remain unknown. In athletes and young, healthy subjects, the NP concentration at rest is not elevated, but strenuous endurance exercise significantly increases NPs. The exercise-induced increase in NPs may be caused by transient myocardial wall stress, cardiomyocyte metabolic changes, or neuroendocrinological response, which may have cytoprotective and growth-regulating effects on the heart. On the other hand, in elderly, overweight/obese subjects, and patients with hypertension, NP concentrations also increase during exercise; however, NP secretion may be more susceptible to cardiac stress compared to young, healthy individuals. Recent studies have shown that NPs are associated with thermogenesis in fat tissue and oxidative capacity in skeletal muscles. NPs may also have a protective role for skeletal muscle in humans, although further studies are warranted to elucidate the physiological mechanism of exercise-induced NP secretion.
      PubDate: 2016-05-31
      DOI: 10.3390/sports4020032
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 33: Self-Reported Use and Reasons among the General
           Population for Using Sports Nutrition Products and Dietary Supplements

    • Authors: Floris Wardenaar, Remko van den Dool, Ingrid Ceelen, Renger Witkamp, Marco Mensink
      First page: 33
      Abstract: The purpose of the present study was to determine the prevalence of dietary supplements (DS’s) and sport nutrition product (SNPs) among the general population, to identify differences for gender, age, and exercise frequency, and to determine the main reasons for use. The study was designed as a web-based questionnaire in a representative sample (n = 1544) of the Dutch population. Sixty-two percent (n = 957) of the respondents reported having used DS’s, SNPs, or both in the last twelve months. Women and older people reported the highest DS use. The highest use of SNPs was reported by regular exercising men and younger people with improving sporting performance as their main objective. Most frequently reported DS’s were multivitamins (28%) and vitamin C (19%)—for SNPs, energy drinks (22%) and isotonic drinks (19%). Health considerations were the most important motivation (DS’s 90% and SNPs 52%), but also performance was substantially reported (DS’s 14% and SNPs 35%). A substantial group of sedentary respondents also reported the use of SNPs. This study confirms that DS’s, SNPs, or both are widely used among the general population. Both health as performance are important reasons for use. It can be questioned whether the use of SNPs fits all respondents’ physical activity needs.
      PubDate: 2016-06-07
      DOI: 10.3390/sports4020033
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 34: Physiological Characteristics of Incoming
           Freshmen Field Players in a Men’s Division I Collegiate Soccer Team

    • Authors: Robert Lockie, DeShaun Davis, Samantha Birmingham-Babauta, Megan Beiley, Jillian Hurley, Alyssa Stage, John Stokes, Tricia Tomita, Ibett Torne, Adrina Lazar
      First page: 34
      Abstract: Freshmen college soccer players will have lower training ages than their experienced teammates (sophomores, juniors, seniors). How this is reflected in field test performance is not known. Freshmen (n = 7) and experienced (n = 10) male field soccer players from the same Division I school completed soccer-specific tests to identify potential differences in incoming freshmen. Testing included: vertical jump (VJ), standing broad jump, and triple hop (TH); 30-m sprint, (0–5, 5–10, 0–10, and 0–30 m intervals); 505 change-of-direction test; Yo-Yo Intermittent Recovery Test Level 2 (YYIRT2); and 6 × 30-m sprints to measure repeated-sprint ability. A MANOVA with Bonferroni post hoc was conducted on the performance test data, and effect sizes and z-scores were calculated from the results for magnitude-based inference. There were no significant between-group differences in the performance tests. There were moderate effects for the differences in VJ height, left-leg TH, 0–5, 0–10 and 0–30 m sprint intervals, and YYIRT2 (d = 0.63–1.18), with experienced players being superior. According to z-score data, freshmen had meaningful differences below the squad mean in the 30-m sprint, YYIRT2, and jump tests. Freshmen soccer players may need to develop linear speed, high-intensity running, and jump performance upon entering a collegiate program.
      PubDate: 2016-06-08
      DOI: 10.3390/sports4020034
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 35: Analysis of Physiological, Technical, and
           Tactical Analysis during a Friendly Football Match of Elite U19

    • Authors: Juan Ortega, Carlos Evangelio, Filipe Clemente, Fernando Martins, Sixto González-Víllora
      First page: 35
      Abstract: The main objective was to analyze a friendly match of youth elite soccer players identifying the variance of tactical and physiological response parameters during the game. In addition, detecting the impact of both halves on player performance. For the purposes of this study twenty-two U19 players were analyzed playing 11v11. Activity profile, heart rate (HR and HRmax), grouped in five different zones were analyzed via Bluetooth technology, technical performance was analyzed by the Team Sport Assessment Procedure (TSAP), and tactical performance was measured by Social Network Analysis. A comparison of heart rate responses showed significant main effects in the halves (p = 0.001; η p 2 = 0.623). A comparison between tactical position and technical performance had significant main effects (p = 0.001; η p 2 = 0.390). Tactical position showed statistically significant effects on tactical prominence (p = 0.002; η p 2 = 0.296). Therefore, fatigue is a component distinguished in technical/tactical parameters, such as volume of play and efficiency index. Results suggest that fatigue effects may constrain technical performance and, for that reason, the use of instruments to monitor the fatigue effect during matches may be suggested.
      PubDate: 2016-06-16
      DOI: 10.3390/sports4020035
      Issue No: Vol. 4, No. 2 (2016)
  • Sports, Vol. 4, Pages 2: Modelling the Progression of Male Swimmers’
           Performances through Adolescence

    • Authors: Shilo Dormehl, Samuel Robertson, Craig Williams
      First page: 2
      Abstract: Insufficient data on adolescent athletes is contributing to the challenges facing youth athletic development and accurate talent identification. The purpose of this study was to model the progression of male sub-elite swimmers’ performances during adolescence. The performances of 446 males (12–19 year olds) competing in seven individual events (50, 100, 200 m freestyle, 100 m backstroke, breaststroke, butterfly, 200 m individual medley) over an eight-year period at an annual international schools swimming championship, run under FINA regulations were collected. Quadratic functions for each event were determined using mixed linear models. Thresholds of peak performance were achieved between the ages of 18.5 ± 0.1 (50 m freestyle and 200 m individual medley) and 19.8 ± 0.1 (100 m butterfly) years. The slowest rate of improvement was observed in the 200 m individual medley (20.7%) and the highest in the 100 m butterfly (26.2%). Butterfly does however appear to be one of the last strokes in which males specialise. The models may be useful as talent identification tools, as they predict the age at which an average sub-elite swimmer could potentially peak. The expected rate of improvement could serve as a tool in which to monitor and evaluate benchmarks.
      PubDate: 2016-01-14
      DOI: 10.3390/sports4010002
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 3: Impact of Nintendo Wii Games on Physical Literacy
           in Children: Motor Skills, Physical Fitness, Activity Behaviors, and

    • Authors: Amanda George, Linda Rohr, Jeannette Byrne
      First page: 3
      Abstract: Physical literacy is the degree of fitness, behaviors, knowledge, and fundamental movement skills (agility, balance, and coordination) a child has to confidently participate in physical activity. Active video games (AVG), like the Nintendo Wii, have emerged as alternatives to traditional physical activity by providing a non-threatening environment to develop physical literacy. This study examined the impact of AVGs on children’s (age 6–12, N = 15) physical literacy. For six weeks children played one of four pre-selected AVGs (minimum 20 min, twice per week). Pre and post measures of motivation, enjoyment, and physical literacy were completed. Results indicated a near significant improvement in aiming and catching (p = 0.06). Manual dexterity significantly improved in males (p = 0.001), and females felt significantly less pressured to engage in PA (p = 0.008). Overall, there appears to be some positive impact of an AVG intervention on components of physical literacy.
      PubDate: 2016-01-15
      DOI: 10.3390/sports4010003
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 4: Acknowledgement to Reviewers of Sports in 2015

    • Authors: Sports Editorial Office
      First page: 4
      Abstract: The editors of Sports would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2015. [...]
      PubDate: 2016-01-21
      DOI: 10.3390/sports4010004
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 5: ZumBeat: Evaluation of a Zumba Dance Intervention
           in Postmenopausal Overweight Women

    • Authors: Anja Rossmeissl, Soraya Lenk, Henner Hanssen, Lars Donath, Arno Schmidt-Trucksäss, Juliane Schäfer
      First page: 5
      Abstract: Physical inactivity is a major public health concern since it increases individuals’ risk of morbidity and mortality. A subgroup at particular risk is postmenopausal overweight women. The aim of this study was to assess the feasibility and effect of a 12-week ZumBeat dance intervention on cardiorespiratory fitness and psychosocial health. Postmenopausal women with a body mass index (BMI) >30 kg/m2 or a waist circumference >94 cm who were not regularly physically active were asked to complete a 12-week ZumBeat dance intervention with instructed and home-based self-training sessions. Before and after the intervention, peak oxygen consumption (VO2peak) was assessed on a treadmill; and body composition and several psychometric parameters (including quality of life, sports-related barriers and menopausal symptoms) were investigated. Of 17 women (median age: 54 years; median BMI: 30 kg/m2) enrolled in the study, 14 completed the study. There was no apparent change in VO2peak after the 12-week intervention period (average change score: −0.5 mL/kg/min; 95% confidence interval: −1.0, 0.1); but, quality of life had increased, and sports-related barriers and menopausal symptoms had decreased. A 12-week ZumBeat dance intervention may not suffice to increase cardiorespiratory fitness in postmenopausal overweight women, but it increases women’s quality of life.
      PubDate: 2016-01-25
      DOI: 10.3390/sports4010005
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 6: “You’re Not Born with Talent” Talented
           Girls’ and Boys’ Perceptions of Their Talents as Football Players

    • Authors: Stig Sæther, Ingar Mehus
      First page: 6
      Abstract: Generally in sports, there is a strong assumption of a connection between skill level in young age and adulthood. Studies have mainly focused on the coaches’ understanding and role in identifying and developing talent. In this article we turn our attention towards the athletes’ perspectives, interviewing talented young football players (five boys and five girls) about their perceptions of their own talent and development. The objective of the article is to investigate how boys and girls perceive their talent and to discuss how various perceptions influence coaching practice in talent development. We introduce the following questions: (a) do the players use a static or dynamic perception of their own talent and (b) do the players consider specific or general skills to be most important in their skill development? Results show that the boys have a more static perception of talent compared to the girls. Furthermore, the boys in this study stress the importance of highly specified skills. The girls have a more balanced view on what is important, but tend to stress the importance of basic skills. The study suggests two potential implications. First, the coaches should be aware of the possible vulnerability following players’ static perception of talent. Second, an exclusive focus on specified skills might make for less optimal preparation for the changing demands young players meet when moving through the different levels of play on their way to high level football. In future research it would be interesting to investigate how players with a lower skill level, not yet regarded as talent, perceive their talent and skill development.
      PubDate: 2016-01-27
      DOI: 10.3390/sports4010006
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 7: Effects of Short-Term Dynamic Constant External
           Resistance Training and Subsequent Detraining on Strength of the Trained
           and Untrained Limbs: A Randomized Trial

    • Authors: Pablo Costa, Trent Herda, Ashley Herda, Joel Cramer
      First page: 7
      Abstract: Short-term resistance training has been shown to increase isokinetic muscle strength and performance after only two to nine days of training. The purpose of this study was to examine the effects of three days of unilateral dynamic constant external resistance (DCER) training and detraining on the strength of the trained and untrained legs. Nineteen men were randomly assigned to a DCER training group or a non-training control group. Subjects visited the laboratory eight times, the first visit was a familiarization session, the second visit was a pre-training assessment, the subsequent three visits were for training sessions (if assigned to the training group), and the last three visits were post-training assessments 1, 2, and 3 (i.e., 48 h, 1 week, and 2 weeks after the final training session). Strength increased in both trained and untrained limbs from pre- to post-training assessment 1 for the training group and remained elevated at post-training assessments 2 and 3 (p ≤ 0.05). No changes were observed in the control (p > 0.05). Possible strength gains from short-term resistance training have important implications in clinical rehabilitation settings, sports injury prevention, as well as other allied health fields such as physical therapy, occupational therapy, and athletic training.
      PubDate: 2016-01-27
      DOI: 10.3390/sports4010007
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 8: Clinical Assessment of Scapula Motion: Scapula
           Upward Rotation and Relationship with Injury in Swimmers

    • Authors: Jo Brown, Rebecca Mellifont, Brendan Burkett
      First page: 8
      Abstract: Abnormal scapulothoracic mechanics and scapulohumeral rhythm are implicated in shoulder pathologies, including glenohumeral impingement and rotator cuff tears. Upward scapula rotation, specifically asymmetry of scapula motion and associations of patterns through range with injury, was investigated in dominant and non-dominant limbs of nationally ranked junior and Paralympic swimmers during competition season. The static and throughout phases measures of upward scapula rotation were: Phase I (start position, 45°), Phase II (45° to 90°), Phase III (90° to 135°) and Phase IV (135° to max). Injury was assessed with a validated questionnaire. Differences between side (dominant and non-dominant), group (junior and Paralympic), and phase were examined. Significant differences (P < 0.05) between groups were identified for dominant side at rest, 45° and 135°, and in phases II and IV (including range). Scapulohumeral rhythm was higher in the non-dominant limb of Paralympic swimmers but in the dominant limb of junior swimmers. Greatest differences in upward rotation between injured and non-injured swimmers were found in Phase 1: 43.6% (3.3°) Paralympic; 73.1% (8°) junior. Results suggest asymmetry of movement in both limbs, through all phases, and at single points in range, should be investigated for assessing injury and developing preventive strategies and rehabilitation protocols.
      PubDate: 2016-01-28
      DOI: 10.3390/sports4010008
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 9: Vertical Jumping Tests versus Wingate Anaerobic
           Test in Female Volleyball Players: The Role of Age

    • Authors: Pantelis Nikolaidis, Jose Afonso, Vicente Clemente-Suarez, Jose Alvarado, Tarak Driss, Beat Knechtle, Gema Torres-Luque
      First page: 9
      Abstract: Single and continuous vertical jumping tests, as well as the Wingate anaerobic test (WAnT), are commonly used to assess the short-term muscle power of female volleyball players; however, the relationship among these tests has not been studied adequately. Thus, the aim of the present study was to examine the relationship of single and continuous vertical jumps with the WAnT in female volleyball players. Seventy adolescent (age 16.0 ± 1.0 years, body mass 62.5 ± 7.1 kg, height 170.4 ± 6.1 cm, body fat 24.2% ± 4.3%) and 108 adult female volleyball players (age 24.8 ± 5.2 years, body mass 66.5 ± 8.7 kg, height 173.2 ± 7.4 cm, body fat 22.0% ± 5.1%) performed the squat jump (SJ), countermovement jump (CMJ), Abalakov jump (AJ), 30 s Bosco test and WAnT (peak power, Ppeak; mean power, Pmean). Mean power in the Bosco test was correlated (low to large magnitude) with Pmean of the WAnT (r = 0.27, p = 0.030 in adolescents versus r = 0.56, p < 0.001 in adults). SJ, CMJ and AJ also correlated with Ppeak (0.28 ≤ r ≤ 0.46 in adolescents versus 0.58 ≤ r ≤ 0.61 in adults) and with Pmean (0.43 ≤ r ≤ 0.51 versus 0.67 ≤ r ≤ 0.71, respectively) of the WAnT (p < 0.05). In summary, the impact of the Bosco test and WAnT on muscle power varied, especially in the younger age group. Single jumping tests had larger correlations with WAnT in adults than in adolescent volleyball players. These findings should be taken into account by volleyball coaches and fitness trainers during the assessment of short-term muscle power of their athletes.
      PubDate: 2016-02-05
      DOI: 10.3390/sports4010009
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 10: Can Fundamental Movement Skill Mastery Be
           Increased via a Six Week Physical Activity Intervention to Have Positive
           Effects on Physical Activity and Physical Self-Perception?

    • Authors: Elizabeth Bryant, Michael Duncan, Samantha Birch, Rob James
      First page: 10
      Abstract: Background: Previous research has suggested a positive relationship between fundamental movement skills (FMS) mastery and physical activity (PA) level. Research conducted on interventions to improve FMS mastery is equivocal and further research is needed. Methods: An intervention group of 82 children (35 boys and 47 girls) and a control group of 83 children (42 boys and 41 girls) were recruited from Years 4 and 5 (mean age ± SD = 8.3 ± 0.4 years) of two schools in Central England. The intervention included a combination of circuits and dancing to music. Pre and post intervention tests were conducted. Tests included: subjective assessment of eight FMS; objective measurement of two FMS; four day pedometer step count recording; height and mass for Body Mass Index (BMI); and the completion of Harter et al.’s (1982) self-perception questionnaire. Results: Following a two (pre to post) by two (intervention and control group) mixed-model ANOVA it was highlighted that the intervention group improved mastery in all eight FMS, and increased both daily steps and physical self-perception. Conclusions: It can be concluded that focussing one Physical Education (PE) lesson per week on the development of FMS has had a positive benefit on FMS, PA level and physical self-perception for the children in this study.
      PubDate: 2016-02-16
      DOI: 10.3390/sports4010010
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 11: Relationship of Two Vertical Jumping Tests to
           Sprint and Change of Direction Speed among Male and Female Collegiate
           Soccer Players

    • Authors: Isaiah McFarland, Jay Dawes, Craig Elder, Robert Lockie
      First page: 11
      Abstract: In collegiate level soccer acceleration, maximal velocity and agility are essential for successful performance. Power production is believed to provide a foundation for these speed qualities. The purpose of this study was to determine the relationship of change of direction speed, acceleration, and maximal velocity to both the counter movement jump (CMJ) and squat jump (SJ) in collegiate soccer players. Thirty-six NCAA Division II soccer players (20 males and 16 females) were tested for speed over 10 and 30 m, CODS (T-test, pro agility) and power (CMJ, SJ). Independent t-tests (p ≤ 0.05) were used to derive gender differences, and Pearson’s correlations (p ≤ 0.05) calculated relationships between the different power and speed tests. Female subjects displayed moderate-to-strong correlations between 30 m, pro agility and T-test with the CMJ (r = −0.502 to −0.751), and SJ (r = −0.502 to −0.681). Moderate correlations between 10 and 30 m with CMJ (r = −0.476 and −0.570) and SJ (r = −0.443 and −0.553, respectively) were observed for males. Moderate to strong relationships exist between speed and power attributes in both male and female collegiate soccer players, especially between CMJ and maximal velocity. Improving stretch shortening cycle (SSC) utilization may contribute to enhanced sport-specific speed.
      PubDate: 2016-02-16
      DOI: 10.3390/sports4010011
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 12: Structural Analysis of Women’s Heptathlon

    • Authors: Freya Gassmann, Michael Fröhlich, Eike Emrich
      First page: 12
      Abstract: The heptathlon comprises the results of seven single disciplines, assuming an equal influence from each discipline, depending on the measured performance. Data analysis was based on the data recorded for the individual performances of the 10 winning heptathletes in the World Athletics Championships from 1987 to 2013 and the Olympic Games from 1988 to 2012. In addition to descriptive analysis methods, correlations, bivariate and multivariate linear regressions, and panel data regressions were used. The transformation of the performances from seconds, centimeters, and meters into points showed that the individual disciplines do not equally affect the overall competition result. The currently valid conversion formula for the run, jump, and throw disciplines prefers the sprint and jump disciplines but penalizes the athletes performing in the 800 m run, javelin throw, and shotput disciplines. Furthermore, 21% to 48% of the variance of the sum of points can be attributed to the performances in the disciplines of long jump, 200 m sprint, 100 m hurdles, and high jump. To balance the effects of the single disciplines in the heptathlon, the formula to calculate points should be reevaluated.
      PubDate: 2016-02-19
      DOI: 10.3390/sports4010012
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 13: Cardiac Autonomic and Salivary Responses to a
           Repeated Training Bout in Elite Swimmers

    • Authors: Rohan Edmonds, Anthony Leicht, Brendan Burkett, Mark McKean
      First page: 13
      Abstract: This study examined the acute training responses of heart rate variability (HRV) and salivary biomarkers (immunoglobulin A and alpha-amylase) following a standardised training bout in Paralympic swimmers. Changes in HRV, sIgA and sAA were documented Monday morning, Monday afternoon and Tuesday morning over a 14-week monitoring period leading into international competition. Magnitude based inferences with effect sizes (ES) were used to assess the practical significance of changes each week. Normal training responses elicited increases in HR, α1, sAA and sIgA, accompanied by decreases in HF(nu), standard deviation of instantaneous RR variability (SD1) and the root mean square of successive differences (RMSSD) from Monday morning to Monday afternoon, and to Tuesday morning with similar week to week responses for most variables. Changes in RMSSD from Monday a.m. to p.m. were likely smaller (less negative) for Week 7 (78/18/3, ES = 0.40) following a competition weekend with similar changes observed from Monday a.m. to Tuesday a.m. (90/5/5, ES = 1.30). In contrast, the change in sAA from Monday a.m. to p.m. was very likely less (more negative) at Week 7 (0/0/99, ES = −2.46), with similar changes observed from Monday a.m. to Tuesday a.m. (0/0/99, ES = −4.69). During the taper period, there were also likely increases in parasympathetic modulations (RMSSD, Weeks 12–14) along with increased immune function (sIgA, Week 13) that demonstrated a favourable state of athlete preparedness. Used together, HRV and sAA provide coaches with valuable information regarding physiological changes in response to training and competition.
      PubDate: 2016-02-24
      DOI: 10.3390/sports4010013
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 14: A Description and Comparison of
           Cardiorespiratory Fitness Measures in Relation to Pitching Performance
           Among Professional Baseball Pitchers

    • Authors: Javair Gillett, J. Dawes, Frank Spaniol, Matthew Rhea, Joe Rogowski, Mitchel Magrini, Roberto Simao, Derek Bunker
      First page: 14
      Abstract: The purpose of this study is to provide descriptive and comparative information regarding the cardiorespiratory fitness of professional baseball pitchers. Twenty-four (n = 24) major league (ML) baseball pitchers (starters n = 14; relievers n = 10) over seven seasons (2007–2013) were evaluated. A modified Bruce protocol and the CardioCoach™ CO2 metabolic analyzer were used to estimate VO2 max and anaerobic threshold (AT) at the beginning of each season. Performance data from each season was utilized to draw inference about pitching performance. One-way Analysis of Variance (ANOVA) was used to compare Starting (S) and Relief (R) pitchers above/below the group mean for VO2 max and AT. Pearson product moment correlations were also used to examine relationships between cardiorespiratory fitness and performance. Significant differences in performance were discovered between S pitchers above/below the overall group mean for VO2 max. (p ≤ 0.05) and for AT in Walks plus Hits per Inning Pitched (WHIP) (p ≤ 0.05) and Earned Run Average (ERA) (p ≤ 0.05). Significant relationships between VO2 max and Walks per 9 Innings (BB/9) (p ≤ 0.05), Home Runs per 9 innings (HR/9) (p ≤ 0.05), Wins (W) (p ≤ 0.05), Fielding Independent Pitching (FIP) (p ≤ 0.01), Strikeouts (K) (p ≤ 0.01), Hits per 9 innings (H/9) (p ≤ 0.01), Strikeouts per 9 innings (K/9) (p ≤ 0.01), ERA (p ≤ 0.01), and WHIP (p ≤ 0.01). Low, but significant, correlations were discovered between AT and WHIP (p ≤ 0.05) and ERA (≤0.05). CONCLUSION: Higher aerobic capacity appears to be more influential for S than R pitchers. Strength and conditioning practitioners should ensure that pitchers, especially S pitchers at the ML level, perform sufficient and appropriate endurance training to support pitching performance.
      PubDate: 2016-02-25
      DOI: 10.3390/sports4010014
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 15: Type of Ground Surface during Plyometric
           Training Affects the Severity of Exercise-Induced Muscle Damage

    • Authors: Hamid Arazi, Roger Eston, Abbas Asadi, Behnam Roozbeh, Alireza Saati Zarei
      First page: 15
      Abstract: The purpose of this study was to compare the changes in the symptoms of exercise-induced muscle damage from a bout of plyometric exercise (PE; 10 × 10 vertical jumps) performed in aquatic, sand and firm conditions. Twenty-four healthy college-aged men were randomly assigned to one of three groups: Aquatic (AG, n = 8), Sand (SG, n = 8) and Firm (FG, n = 8). The AG performed PE in an aquatic setting with a depth of ~130 cm. The SG performed PE on a dry sand surface at a depth of 20 cm, and the FG performed PE on a 10-cm-thick wooden surface. Plasma creatine kinase (CK) activity, delayed onset muscle soreness (DOMS), knee range of motion (KROM), maximal isometric voluntary contraction (MIVC) of the knee extensors, vertical jump (VJ) and 10-m sprint were measured before and 24, 48 and 72 h after the PE. Compared to baseline values, FG showed significantly (p < 0.05) greater changes in CK, DOMS, and VJ at 24 until 48 h. The MIVC decreased significantly for the SG and FG at 24 until 48 h post-exercise in comparison to the pre-exercise values. There were no significant (p > 0.05) time or group by time interactions in KROM. In the 10-m sprint, all the treatment groups showed significant (p < 0.05) changes compared to pre-exercise values at 24 h, and there were no significant (p > 0.05) differences between groups. The results indicate that PE in an aquatic setting and on a sand surface induces less muscle damage than on a firm surface. Therefore, training in aquatic conditions and on sand may be beneficial for the improvement of performance, with a concurrently lower risk of muscle damage and soreness.
      PubDate: 2016-03-01
      DOI: 10.3390/sports4010015
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 16: How Confident Can We Be in Modelling Female
           Swimming Performance in Adolescence?

    • Authors: Shilo Dormehl, Samuel Robertson, Craig Williams
      First page: 16
      Abstract: The purpose of this research was to determine the expected progression of adolescent female swimming performances using a longitudinal approach. The performances of 514 female swimmers (12–19 year olds) who participated in one or more FINA-regulated annual international schools’ swimming championships over an eight-year period were analysed. Quadratic functions for each of the seven individual events (50, 100, 200 m freestyle, 100 m backstroke, breaststroke, butterfly, 200 m individual medley) were determined using mixed linear models. The predicted threshold of peak performance ranged from 16.8 ± 0.2 (200 m individual medley) to 20.6 ± 0.1 (100 m butterfly) years of age, preceded by gradual rates of improvement (mean rate of 1.6% per year). However, following cross validation, only three events (100 m backstroke, 200 m individual medley and 200 m freestyle) produced reliable models. Identifying the factors that contribute to the progression of female performance in this transitory period of life remains challenging, not least since the onset of puberty is likely to have occurred prior to reaching 12 years of age, the minimum competition age for this championship.
      PubDate: 2016-03-03
      DOI: 10.3390/sports4010016
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 17: The Age in Swimming of Champions in World
           Championships (1994–2013) and Olympic Games (1992–2012): A
           Cross-Sectional Data Analysis

    • Authors: Beat Knechtle, Nicola Bragazzi, Stefan König, Pantelis Nikolaidis, Stefanie Wild, Thomas Rosemann, Christoph Rüst
      First page: 17
      Abstract: (1) Background: We investigated the age of swimming champions in all strokes and race distances in World Championships (1994–2013) and Olympic Games (1992–2012); (2) Methods: Changes in age and swimming performance across calendar years for 412 Olympic and world champions were analysed using linear, non-linear, multi-level regression analyses and MultiLayer Perceptron (MLP); (3) Results: The age of peak swimming performance remained stable in most of all race distances for world champions and in all race distances for Olympic champions. Longer (i.e., 200 m and more) race distances were completed by younger (-20 years old for women and -22 years old for men) champions than shorter (i.e., 50 m and 100 m) race distances (-22 years old for women and -24 years old for men). There was a sex difference in the age of champions of -2 years with a mean age of -21 and -23 years for women and men, respectively. Swimming performance improved in most race distances for world and Olympic champions with a larger trend of increase in Olympic champions; (4) Conclusion: Swimmers at younger ages (<20 years) may benefit from training and competing in longer race distances (i.e., 200 m and longer) before they change to shorter distances (i.e., 50 m and 100 m) when they become older (>22 years).
      PubDate: 2016-03-04
      DOI: 10.3390/sports4010017
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 18: A Comparison between Chocolate Milk and a Raw
           Milk Honey Solution’s Influence on Delayed Onset of Muscle Soreness

    • Authors: Andrew Hatchett, Christopher Berry, Claudia Oliva, Douglas Wiley, Jacob St. Hilaire, Alex LaRochelle
      First page: 18
      Abstract: This investigation sought to examine the effect that a chocolate milk solution (CMS) and a raw milk solution (RMS) had on lower extremity induced delayed onset of muscle soreness (DOMS). Twenty trained male participants completed a set of questionnaires, prior to completing a lower extremity DOMS protocol, to determine the level of discomfort and functional limitations. Once the DOMS protocol was completed, participants were randomly assigned to either the CM or RM group. Once assigned, participants ingested 240 mL of the respective solution and completed the same set of questionnaires immediately post, 24-, 48- and 72-h post DOMS protocol. Additionally, for 10 days post-ingestion participants were contacted to learn if any negative effects were experienced as a result of ingesting either solution. Both groups reported an increase in lower extremity discomfort at each data collection interval post-DOMS protocol (post, 24-, 48- and 72-h). Participants assigned to the RM group reported high discomfort post and a relative decline in discomfort from immediately post-DOMS protocol to 72-h post. The RMS group reported substantially less discomfort at 72-h when compared to the CMS group. Ingestion of a raw milk solution immediately post strength exercise can substantially reduce the level of self-reported discomfort associated with DOMS.
      PubDate: 2016-03-07
      DOI: 10.3390/sports4010018
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 19: Lateral Squats Significantly Decrease Sprint
           Time in Collegiate Baseball Athletes

    • Authors: Jason White, Trevor Dorian, Margaret Jones
      First page: 19
      Abstract: The purpose was to examine the effect of prior performance of dumbbell lateral squats (DBLS) on an agility movement-into-a-sprint (AMS) test. Twelve collegiate, resistance-trained, baseball athletes participated in three sessions separated by three days. Session One consisted of AMS baseline test, DBLS 5-RM test, and experimental protocol familiarization. Subjects were randomly assigned the protocol order for Sessions Two and Three, which consisted of warm up followed by 1-min sitting (no-DBLS) or performing the DBLS for 1 × 5 repetitions @ 5RM for each leg. Four minutes of slow recovery walking preceded the AMS test, which consisted of leading off a base and waiting for a visual stimulus. In reaction to stimulus, subjects exerted maximal effort while moving to the right by either pivoting or drop stepping and sprinting for 10 yards (yd). In Session Three, subjects switched protocols (DBLS, no-DBLS). Foot contact time (FCT), stride frequency (SF), stride length (SL), and 10-yd sprint time were measured. There were no differences between conditions for FCT, SF, or SL. Differences existed between DBLS (1.85 ± 0.09 s) and no-DBLS (1.89 ± 0.10 s) for AMS (p = 0.03). Results from the current study support the use of DBLS for performance enhancement prior to performing the AMS test.
      PubDate: 2016-03-07
      DOI: 10.3390/sports4010019
      Issue No: Vol. 4, No. 1 (2016)
  • Sports, Vol. 4, Pages 20: Physical and Physiological Characteristics of
           Judo Athletes: An Update

    • Authors: Gema Torres-Luque, Raquel Hernández-García, Raquel Escobar-Molina, Nuria Garatachea, Pantelis Nikolaidis
      First page: 20
      Abstract: Judo competition is characterized structurally by weight category, which raises the importance of physiological control training in judo. The aim of the present review was to examine scientific papers on the physiological profile of the judokas, maintenance or loss of weight, framing issues, such as anthropometric parameters (body fat percentage), heart rate responses to training and combat, maximal oxygen uptake, hematological, biological and hormones indicators. The values shown in this review should be used as a reference for the evaluation of physical fitness and the effectiveness of training programs. Hence, this information is expected to contribute to the development of optimal training interventions aiming to achieve maximum athletic performance and to maintain the health of judokas.
      PubDate: 2016-03-10
      DOI: 10.3390/sports4010020
      Issue No: Vol. 4, No. 1 (2016)
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