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Journal Cover Journal of Sport and Health Science
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  This is an Open Access Journal Open Access journal
   ISSN (Print) 2095-2546
   Published by Elsevier Homepage  [2801 journals]
  • Neighborhood environment, physical activity, and quality of life in
           adults: Intermediary effects of personal and psychosocial factors

    • Abstract: Publication date: Available online 25 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Eleni Theodoropoulou, Nektarios Stavrou, Konstantinos Karteroliotis
      Background Studies have indicated that there is a positive and indirect relationship between physical activity (PA) and quality of life (QoL). The current study examined this relationship through a social cognitive model with consideration to the intermediary effects of exercise self-efficacy, and physical (PCS) and psychological (MCS) health. Additionally, this model was widened to include concepts from the ecological theory, and any causal associations among neighborhood environment, PA, and QoL. Methods Six hundred and eighty four physically active adults (39.16 ± 13.52 years, mean ± SD), living in Athens, Greece, completed a series of questionnaires measuring PA, QoL, exercise self-efficacy, PCS, MCS, neighborhood environment, and family and friend support for PA. The examined models were analyzed using structural equation modeling. Results The social cognitive and ecological models proved to be of appropriate fit. Within the social cognitive model, PA positively affected QoL through the mediating effects of exercise self-efficacy, PCS, and MCS. With regards to the ecological model, neighborhood environment positively influenced QoL through the intermediary effects of family support for PA, exercise self-efficacy, PA, PCS, and MCS. Conclusion Results indicated that the most important mediators in the examined models were exercise self-efficacy and health. Further, findings demonstrated the role of neighborhood environment in enhancing PA and QoL. Future studies should be carried out applying longitudinal data for a better understanding of these associations over time.


      PubDate: 2016-02-01T17:44:13Z
       
  • Preparatory training at tenuates drastic response of the insulin-like
           growth factor binding protein 1 at the point of maximal oxygen consumption
           in handball players

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Olgica Nedić, Miloš Šunderić, Goran Miljuš, Zoran Valdevit, Vladimir Jakovljević, Marija Glibetić, Vesna Vučić
      Background Intensive exercise changes physiological need for glucose and several biochemical pathways responsible for its metabolism response. Among them are those which involve insulin, insulin-like growth factor (IGF)-I, and IGF-binding proteins (IGFBPs). Different types and degrees of exercise, as well as an athlete's fitness, may induce a range of responses regarding concentrations and time needed for the alteration. The idea of the work was to find out whether and how insulin/IGF axis responds to additional physical activity in the already trained subjects and if so, is the adaptation potentially beneficial from the aspect of metabolic control. Methods The effect of 4-week intensive training on campus (preparatory training) on the levels of insulin, IGF-I, and IGFBPs during maximal progressive exercise test (MPET) on a treadmill was compared to the results obtained during MPET conducted after a regular training season of a female elite handball team (n = 17, age 17 ± 1 years old, height 171 ± 8 cm, weight 65 ± 8 kg and BMI 22 ± 1 kg/m2 at the beginning of the study; there were no significant changes at the end). Serum samples were obtained from players immediately before the test (basal), at the end of the test after reaching the point of maximal oxygen consumption (VO2max), and after recovery. Results The concentration of insulin decreased at VO2max, but remained higher in players after preparatory training (12.2 ± 2.5 vs. 8.9 ± 4.4 mU/L, p = 0.049). The level of IGFBP-1 decreased in players at VO2max in either case of training, but it remained much higher in tests performed after the preparatory regime (1.4 ± 0.5 densitometric units) than before (0.7 ± 0.3 densitometric units, p = 0.029). Concentrations of IGF-I, IGFBP-2, -3, and -4 did not change significantly. Conclusion As intensive physical activity requires efficient energy supply, it seemed relevant to investigate changes of the metabolic hormones responsible for glucose control during MPET which can be compared (in terms of the exercise overload) with the episodes of very intensive games. The inverse relation between insulin and IGFBP-1 was lost during MPET, as these two molecules changed in the same direction. The results obtained suggest less severe stress-induced depression of insulin and IGFBP-1 after preparatory training. But another metabolic mechanism cannot be excluded, and that is potentially impaired insulin sensitivity resulting in higher level of IGFBP-1. Taking into account both possible explanations, the changes seen cannot be, at the moment, defined as either beneficial or not for athletes' glucose control.


      PubDate: 2016-01-25T13:26:03Z
       
  • Multiscale entropy: a tool for understanding the complexity of postural
           control

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Michael A. Busa, Richard E.A. van Emmerik
      Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing. Disruption to a large number of physiological processes operating at different time scales can lead to alterations in postural center of pressure (COP) fluctuations. Multiscale entropy (MSE) has been used to identify differences in fluctuations of postural COP time series between groups with and without known physiological impairments at multiple time scales. The purpose of this paper is to: 1) review basic elements and current developments in entropy techniques used to assess physiological complexity; and 2) identify how MSE can provide insights into the complexity of physiological systems operating at multiple time scales that underly the control of posture. We review and synthesize evidence from the literature providing support for MSE as a valuable tool to evaluate the breakdown in the physiological processes that accompany changes due to aging and disease in postural control. This evidence emerges from observed lower MSE values in individuals with multiple sclerosis, idiopathic scoliosis, and in older individuals with sensory impairments. Finally, we suggest some future applications of MSE that will allow for further insight into how physiological deficits impact the complexity of postural fluctuations; this information may improve the development and evaluation of new therapeutic interventions.


      PubDate: 2016-01-25T13:26:03Z
       
  • p < 0.05, < 0.01, < 0.001, < 0.0001, <
           0.00001, < 0.000001, or < 0.0000001 …

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Weimo Zhu



      PubDate: 2016-01-25T13:26:03Z
       
  • Time-dependent gene expression analysis after mouse skeletal muscle
           contusion

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Weihua Xiao, Yu Liu, Beibei Luo, Linlin Zhao, Xiaoguang Liu, Zhigang Zeng, Peijie Chen
      Background Though the mechanisms of skeletal muscle regeneration are deeply understood, those involved in muscle contusion, one of the most common muscle injuries in sports medicine clinics, are not.The objective of this study is to explore the mechanisms involved in muscle regeneration after contusion injury. Methods In this study, a total of 72 mice were used. Eight of them were randomly chosen for the control group, while the rest were subjected to muscle contusion. Subsequently, their gastrocnemius muscles were harvested at different time points. The changes in muscle morphology were assessed by hematoxylin and eosin (HE) stain.In addition, the gene expression was analyzed by real-time polymerase chain reaction. Results The data showed that the expression of many genes, i.e., specific markers of immune cells and satellite cells, regulatory factors for muscle regeneration, cytokines, and chemokines, increased in the early stages of recovery, especially in the first three days. Furthermore, there were strict rules in the expression of these genes. However, almost all the genes returned to normal at 14 days post-injury. Conclusion These data suggest that the sequence of immune cells invaded after muscle contusion was neutrophils, M1 macrophages and M2 macrophages. Some CC (CCL2, CCL3, and CCL4) and CXC (CXCL10) chemokines may be involved in the chemotaxis of these immune cells. HGF may be the primary factor to activate the satellite cells after muscle contusion. Moreover,2 weeks is needed to recover when acute contusion happens as used in this study.


      PubDate: 2016-01-25T13:26:03Z
       
  • The effects of total soy saponins on free radicals in the quadriceps
           femoris, serum testosterone, LDH, and BUN of exhausted rats

    • Abstract: Publication date: Available online 22 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Zhigang Liu, Ruixin Nie, Yun Liu, Zhouhong Li, Chenxi Yang, Zhengying Xiong
      Purpose The aim of this study was to investigate the impact of total soy saponins (TS) on the free radical metabolism from the quadriceps femoris muscle, serum testosterone, lactate dehydrogenase (LDH) , and blood urea nitrogen (BUN) in rats exercised to exhaustion. Methods A one-time exhausted treadmill exercise session was used. Sprague-Dawley rats were divided into four groups: a control group—animals receiving no TS and no exercise (NTSNE) , animals receiving TS and no exercise group (TSNE) , animals receiving no TS and exercised to exhaustion group (NTSE) , and animals receiving TS and exercised to exhaustion group (TSE) . The TSNE and TSE groups were fed TS at a dosage of 20 mg/kg body weight once per day for 2 weeks. The NTSE group was given a placebo, and the NTSNE group was not given any treatment. The NTSE and TSE groups were exercised at speed of 30m/min on treadmill until exhausted. The exercise time and exercise distance were recorded when the rats became exhausted and the rats were then decapitated and anatomized immediately. A 10% homogenate of the quadriceps femoris tissue was prepared. The levels of superoxide dismutase (SOD) , catalase (CAT) , malondialdehyde (MDA) , glutathione peroxidase (GSH-Px) , glutathione reductase (GR) , reduced glutathione (GSH) , total antioxidant capacity (T-AOC) , LDH, BUN, and serum testosterone levels were tested. Results TS significantly increased the exercise time by 20.62% (p < 0.05) . The MDA levels were decreased significantly in the TSNE group than in NTSNE group (p < 0.05) , the T-AOC levels increased significantly in the TSNE group than the other three groups (p < 0.01, p < 0.05, p < 0.05) . The LDH activity significantly increased in the NTSE group than in TSNE group (p < 0.05) . The BUN levels significantly increased in the NTSE group than in the other three groups (p < 0.01, p < 0.01, p < 0.05) . The serum testosterone levels increased significantly in the TSNE group than the other three groups (p < 0.01) . SOD, CAT, GSH-Px, GR, and GSH were not statistically different among the groups. Conclusion TS can significantly improve the exercised rat's serum testosterone levels and antioxidant activity in their quadriceps femoris to varying degrees, decrease MDA and serum LDH and BUN levels, increase the exercise time, and delay the occurrence of the fatigue.


      PubDate: 2016-01-25T13:26:03Z
       
  • Confirmatory factor analysis of the VISA-p scale and measurement
           invariance across sexes in athletes with patellar tendinopathy

    • Abstract: Publication date: Available online 22 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Sergio Hernandez-Sanchez, Ferran Abat, María D. Hidalgo, Antonio I. Cuesta-Vargas, Victor Segarra, Jose M. Sanchez-Ibañez, Antonia Gomez-Conesa
      Purpose The Victorian Institute of Sport Assessment-Patella Scale (VISA-P) is the most condition-specific patient-reported outcome measure used to assess symptom severity in athletes with patellar tendinopathy. Previous exploratory factor analyses have been conducted to evaluate the scale's dimensionality, with inconsistent results, and the factor structure of the scale remains unclear. The aims of the present study were to determine the factorial structure of the VISA-Pusing confirmatory factor analysis (CFA) and test measurement invariance across sexes. Methods The study included a convenience sample of 249 Spanish athletes with patellar tendinopathy. CFA was performed to assess factorial validity. Hypothesized 1- and 2-factor models were tested. Measurement invariance across sexes was evaluated via multi-group CFA with several fit indices, using EQS 6.1 software. Results The internal consistency coefficient was 0.74. Several CFA models were examined and the 1-factor model in which errors for items 7 and 8 were correlated, showed acceptable fit in terms of comparative fit index (CFI) and goodness-of-fit index (GFI) statistics (CFI = 0.93; GFI = 0.94; standardized root mean square residual = 0.06; root mean square error of approximation = 0.10; 90% confidence interval = 0.08–0.13). This model was invariant across sexes. Conclusion The 1-factor model of the Spanish version of the VISA-P (VISA-P-Sp) in which errors for items 7 and 8 were correlated demonstrated relative fit in CFA. Scores obtained via VISA-P-Sp can be compared between men and women without sex bias. Further studies should examine the VISA-P and other single-score patient-reported outcome measures concurrently.


      PubDate: 2016-01-25T13:26:03Z
       
  • Multi-scale interactions in interpersonal coordination

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Tehran J. Davis, Thomas R. Brooks, James A. Dixon
      Background Interpersonal coordination is an essential aspect of daily life, and crucial to performance in cooperative and competitive team sports. While empirical research has investigated interpersonal coordination using a wide variety of analytical tools and frameworks, to date very few studies have employed multifractal techniques to study the nature of interpersonal coordination across multiple spatiotemporal scales. In the present study we address this gap. Methods We investigated the dynamics of a simple dyadic interpersonal coordination task where each participant manually controlled a virtual object in relation to that of his or her partner. We tested whether the resulting hand-movement time series exhibits multi-scale properties and whether those properties are associated with successful performance. Results Using the formalism of multifractals, we show that the performance on the coordination task is strongly multi-scale, and that the multi-scale properties appear to arise from interaction-dominant dynamics. Further, we find that the measure of across-scale interactions, multifractal spectrum width, predicts successful performance at the level of the dyad. Conclusion The results are discussed with respect to the implications of multifractals and interaction-dominance for understanding control in an interpersonal context.


      PubDate: 2016-01-25T13:26:03Z
       
  • Comparing dynamical systems concepts and techniques for biomechanical
           analysis

    • Abstract: Publication date: Available online 18 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Richard E.A. van Emmerik, Scott W. Ducharme, Avelino Amado, Joseph Hamill
      Traditional biomechanical analyses of human movement are generally derived from linear mathematics. While these methods can be useful in many situations, they do not describe behaviors in human systems that are predominately nonlinear. For this reason, nonlinear analysis methods based on a dynamical systems approach have become more prevalent in recent literature. These analysis techniques have provided new insights into how systems (1) maintain pattern stability, (2) transition into new states, and (3) are governed by short and long-term (fractal) correlational processes at different spatio-temporal scales. These different aspects of system dynamics are typically investigated using concepts related to variability, stability, complexity, and adaptability. The purpose of this paper is to compare and contrast these different concepts and demonstrate that, although related, these terms represent fundamentally different aspects of system dynamics. In particular, we argue that variability should not uniformly be equated with stability or complexity of movement. In addition, current dynamic stability measures based on nonlinear analysis methods (such as the finite maximal Lyapunov exponent) can reveal local instabilities in movement dynamics, but the degree to which these local instabilities relate to global postural and gait stability and the ability to resist external perturbations remains to be explored. Finally, systematic studies are needed to relate observed reductions in complexity with aging and disease to the adaptive capabilities of the movement system and how complexity changes as a function of different task constraints.


      PubDate: 2016-01-20T13:11:51Z
       
  • Can coordination variability identify performance factors and skill level
           in competitive sport? The case of race walking

    • Abstract: Publication date: Available online 13 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Dario Cazzola, Gaspare Pavei, Ezio Preatoni
      Background Marginal changes in the execution of competitive sports movements can represent a significant change for performance success. However, such differences may emerge only at certain execution intensities and are not easily detectable through conventional biomechanical techniques. This study aimed to investigate if and how competition standard and progression speed affect race walking kinematics from both a conventional and a coordination variability perspective. Methods Fifteen experienced athletes divided into three groups (Elite, International, and National) were studied while race walking on a treadmill at two different speeds (12.0 and 15.5 km/h). Basic gait parameters, the angular displacement of the pelvis and lower limbs, and the variability in continuous relative phase between six different joint couplings were analyzed. Results Most of the spatio-temporal, kinematic, and coordination variability measures proved sensitive to the change in speed. Conversely, non-linear dynamics measures highlighted differences between athletes of different competition standard when conventional analytical tools were not able to discriminate between different skill levels. Continuous relative phase variability was higher for National level athletes than International and Elite in two couplings (pelvis obliquity—hip flex/extension and pelvis rotation—ankle dorsi/plantarflexion) and gait phases (early stance for the first coupling, propulsive phase for the second) that are deemed fundamental for correct technique and performance. Conclusion Measures of coordination variability showed to be a more sensitive tool for the fine detection of skill-dependent factors in competitive race walking, and showed good potential for being integrated in the assessment and monitoring of sports motor abilities.


      PubDate: 2016-01-15T20:48:41Z
       
  • Heart rate variability to assess ventilatory thresholds in professional
           basketball players

    • Abstract: Publication date: Available online 12 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Domingo Jesús Ramos-Campo, Jacobo A. Rubio-Arias, Vicente Ávila-Gandía, Cristian Marín-Pagán, Antonio Luque, Pedro E. Alcaraz
      Purpose The aim of this study was to determine if heart rate variability (HRV) during incremental test could be used to estimate ventilatory threshold (VT) in professional basketball players, with sufficient precision to be used in their training. Furthermore, the second aim was to analyse the association between HRV and three methods of VT determination by gas analysis. Methods Twenty-four professional basketball players (age: 23.4 ± 4.9 years; height: 195.4 ± 9.8 cm; body mass: 92.2 ± 11.9 kg) performed an incremental running test to exhaustion. First ventilatory threshold (VT1) was determined by ventilatory equivalent (VE) and HRV and second ventilatory threshold (VT2) was determined by three methods of gases analysis (V-slope, VE and gas exchange ratio (R) and HRV). Pearson's coefficient (r) was used to detect differences between data and the strength of each relationship. The mean of absolute differences and Bland–Altman analysis were used to evaluate whether there was agreement. Results The results showed no significant differences in HR and oxygen consumption (VO2) at VT1 between the two methods. Furthermore, no significant differences among the methods of gases analysis and HRV were observed in speed, HR, and VO2 at VT2. Moreover, VTs estimated using HRV and gas methods were significantly correlated. Correlation was higher between R and HRV (r = 0.96) and VE and HRV (r = 0.96) than V-slope and HRV (r = 0.90). Conclusion These findings provide a practical, inexpensive approach for evaluating specific training loads when determining VT2 in basketball players. Therefore, HRV is an alternative method to determine VT2 without the application of expensive technology that limits its use to laboratories.


      PubDate: 2016-01-15T20:48:41Z
       
  • Correlates of long-term physical activity adherence in women

    • Abstract: Publication date: Available online 12 January 2016
      Source:Journal of Sport and Health Science
      Author(s): H. Sun, C.A. Vamos, S.B. Flory, R. DeBate, E.L. Thompson, J. Bleck
      Background Little is known about the factors that may influence women's adherence to moderate to vigorous physical activity (MVPA) using longitudinal data. The purpose of this study was to examine the correlates of long-term physical activity (PA) participation among women. Methods Female data from Waves I, III, and IV (n = 5,381) of the National Longitudinal Study of Adolescent to Adult Health (Add Health) were used for the analysis. The outcome of PA adherence was operationalized as (1) consistently physically active (at least 5 instances during the week) in both Waves III and IV (during adulthood), and (2) consistently not physically active or only physically active in either Wave III or IV. Predictor variables from Wave I (during adolescence) included race/ethnicity, PA level, self-perception of being physically fit, general health status, attempt to change weight, parents' income level, parents' education, well-being, depression, access to PA resources, days of physical education (PE), and grade level. Crude and adjusted logistic regression models were utilized to estimate the adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) for the outcome variable. Results PA levels during adolescence significantly predicted PA adherence (aOR = 1.67, 95% CI 1.35–2.05). Additionally, wanting to lose weight (aOR = 1.49, 95% CI 1.20–1.85), using fitness center in the neighborhood (aOR = 1.28, 95% CI 1.04–1.58), and having 5 days of PE a week (aOR = 1.50, 95% CI 1.09–2.06) were significant predictors. Women who did not perceive being physically fit (aOR = 0.65, 95% CI 0.45–0.95) and Black, non-Hispanics (aOR = 0.59, 95% CI 0.43–0.81) were less likely to adhere to PA. Conclusion The findings suggested that physically active adolescents were more likely to become active adults. Future research should address interventions (e.g., PE program, community resources) that may promote lifetime PA in women, with the goal of decreasing morbidity and mortality.


      PubDate: 2016-01-15T20:48:41Z
       
  • Postural control deficits identify lingering post-concussion neurological
           deficits

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Thomas A. Buckley, Jessie R. Oldham, Jaclyn B. Caccese
      Concussion, or mild traumatic brain injury, incidence rates have reached epidemic levels and impaired postural control is a cardinal symptom. The purpose of this review is to provide an overview of the linear and non-linear assessments of post-concussion postural control. The current acute evaluation for concussion utilizes the subjective balance error scoring system (BESS) to assess postural control. While the sensitivity of the overall test battery is high, the sensitivity of the BESS is unacceptably low and, with repeat administration, is unable to accurately identify recovery. Sophisticated measures of postural control, utilizing traditional linear assessments, have identified impairments in postural control well beyond BESS recovery. Both assessments of quiet stance and gait have identified lingering impairments for at least 1 month post-concussion. Recently, the application of non-linear metrics to concussion recovery have begun to receive limited attention with the most commonly utilized metric being approximate entropy (ApEn). ApEn, most commonly in the M/L plane, has successfully identified impaired postural control in the acute post-concussion timeframe even when linear assessments of instrumented measures are equivalent to healthy pre-injury values; unfortunately these studies have not gone beyond the acute phase of recovery. One study has identified lingering deficits in postural control, utilizing Shannon and Renyi entropy metrics, which persist at least through clinical recovery and return to participation. Finally, limited evidence from two studies suggest that individuals with a previous history of a single concussion, even months or years prior, may display altered ApEn metrics. Overall, non-linear metrics provide a fertile area for future study to further the understanding of postural control impairments acutely post-concussion and address the current challenge of sensitive identification of recovery.


      PubDate: 2016-01-15T20:48:41Z
       
  • Self-perceptions and social-emotional classroom engagement following
           structured physical activity among preschoolers: A feasibility study

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Spyridoula Vazou, Constantine Mantis, Gayle Luze, Jacqueline S. Krogh
      Background The well-rounded development of the child, including physical, cognitive, emotional, and social health, may be the most efficient route to well-being and academic success. The primary goal was to investigate the feasibility of implementing a 12-week structured program of physical activity (PA) incorporating cognitive, social, and emotional elements in preschool. Additionally, this study, using a within-subject design, examined the acute effects of a PA session on classroom engagement and changes on perceived competence and peer acceptance from the first to the last week of the program. Methods Twenty-seven preschoolers (M age = 4.2 years) completed the Pictorial Scale of Perceived Competence and Social Acceptance for Young Children before and after a twice-weekly PA program. Unobtrusive classroom observations were conducted for verbal, social, and affective engagement during the first and last week of the program, both following a structured PA session (experimental day) and on a day without PA (control day). Treatment fidelity was monitored to ensure that the intervention was delivered as designed. Results The children exhibited longer periods of verbal and social engagement during classroom periods that followed PA sessions than on non-PA days. Children also expressed more positive affect following PA sessions during the last week of the PA program. Despite high baseline scores, perceptions of general competence increased meaningfully (η 2 = 0.15, p = 0.05), driven by increases in perceptions of cognitive competence (η 2 = 0.15, p = 0.06). Conclusion This study demonstrates the feasibility of providing structured PA program to preschoolers. Moreover, these initial findings suggest that purposely designed, structured PA may help advance the social-emotional engagement and perceived competence of preschool children.


      PubDate: 2016-01-15T20:48:41Z
       
  • Parental social support, perceived competence and enjoyment in school
           physical activity

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Bo Shen, Erin Centeio, Alex Garn, Jeffrey Martin, Noel Kulik, Cheryl Somers, Nate McCaughtry
      Background Beginning in the elementary school years, there are differences among children on how they perceive their competence in physical activity (PA). Children's competence perceptions may influence their affective reactions to PA. A crucial question is how to motivate children who hold low competence perceptions to enhance their enjoyment and PA involvement. Because parents play critical roles in children's development and socialization, social support from parents can be an important factor to complement teachers' effort to enhance children's enjoyment and PA involvement. Purpose In this research we identified the associations among children's beliefs about parental social support, perceived competence and enjoyment in school PA. Methods Three hundred twenty children (9–11 years old) participated in a two-wave study. At the first wave, children completed questionnaires measuring their beliefs about parental social support, perceived competence and enjoyment in school PA; they reported their enjoyment again 8 months later at the second wave. Results Both concurrent and longitudinal analyses revealed that beliefs about parental social support were important factors associated with children's enjoyment in school PA, especially among girls with low competence perceptions. Conclusion Family socialization factors should be taken into consideration. The efficacy of individual and community-level strategies should be included and evaluated when designing effective intervention strategies that enhance children's PA in school.


      PubDate: 2016-01-15T20:48:41Z
       
  • Heat dissipating upper body compression garment: Thermoregulatory,
           cardiovascular, and perceptual responses

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Iker Leoz-Abaurrea, Nicholas Tam, Roberto Aguado-Jiménez
      Purpose The aim of the present study was to determine the effects of an upper body compression garment (UBCG) on thermoregulatory responses during cycling in a controlled laboratory thermoneutral environment (~23°C). A secondary aim was to determine the cardiovascular and perceptual responses when wearing the garment. Methods Sixteen untrained participants, (age 21.3 ± 5.7 years, VO2peak 50.88 ± 8.00 mL/min/kg, mean ± SD) performed two cycling trials in a thermoneutral environment (~23°C) wearing either UBCG or Control (Con) garment. Testing consisted of a 5-min rest on a cycle ergometer, followed by 4 bouts of cycling for 14 min at ~50% VO2peak, with 1-min rest between each bout. At the end of these bouts there was 10-min of passive recovery. During the entire protocol rectal temperature (Trec), skin temperature (Tskin), mean body temperature (Tbody) and heat storage (HS) were measured. Heart rate (HR), VO2, pH, hematocrit (Hct), plasma electrolytes, weight loss (Wloss), and perceptual responses were also measured. Results There were no significant differences between garments for Tskin, HS, HR, VO2, pH, Hct, plasma electrolyte concentration, Wloss, and perceptual responses during the trial. Trec did not differ between garment conditions during rest, exercise, or recovery although a greater reduction in Trec wearing UBCG (p = 0.01) was observed during recovery. Lower Tbody during recovery was found when wearing UBCG (36.82 ± 0.3°C vs. 36.99 ± 0.24°C). Conclusion Wearing a UBCG did not benefit thermoregulatory, cardiovascular, and perceptual responses during exercise although it was found to lower Tbody during recovery, which suggests that it could be used as a recovery tool after exercise.


      PubDate: 2016-01-15T20:48:41Z
       
  • The relationship between intermittent limit cycles and postural
           instability associated with Parkinson's disease

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): James R. Chagdes, Jessica E. Huber, Meredith Saletta, Meghan Darling-White, Arvind Raman, Shirley Rietdyk, Howard N. Zelaznik, Jeffrey M. Haddad
      Background Many disease-specific factors such as muscular weakness, increased muscle stiffness, varying postural strategies, and changes in postural reflexes have been shown to lead to postural instability and fall risk in people with Parkinson's disease (PD). Recently, analytical techniques, inspired by the dynamical systems perspective on movement control and coordination, have been used to examine the mechanisms underlying the dynamics of postural declines and the emergence of postural instabilities in people with PD. Methods A wavelet-based technique was used to identify limit cycle oscillations (LCOs) in the anterior–posterior (AP) postural sway of people with mild PD (n = 10) compared to age-matched controls (n = 10). Participants stood on a rigid foam surface while completing a dual task (speaking). Results There was no significant difference in the RMS of center of pressure between groups. Three out of 10 participants with PD demonstrated LCOs on the foam surface, while none in the control group demonstrated LCOs. An inverted pendulum model of bipedal stance was used to demonstrate that LCOs occur due to disease specific changes associated with PD: time-delay and neuromuscular feedback gain. Conclusion Overall, the LCO analysis and mathematical model appear to capture the subtle postural instabilities associated with mild PD. In addition, these findings provide insights into the mechanisms that lead to the emergence of unstable posture in patients with PD.


      PubDate: 2016-01-15T20:48:41Z
       
  • Effects of 12 weeks of barefoot running on foot strike patterns,
           inversion–eversion and foot rotation in long-distance runners

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Pedro A. Latorre-Román, Felipe García-Pinillos, Víctor M. Soto-Hermoso, Marcos Muñoz Jiménez
      Purpose The purpose of this study was to determine the effects of 12 weeks of barefoot running on foot strike patterns, inversion–eversion and foot rotation in long-distance runners. Methods Thirty-one endurance runners with no experience in barefoot running were randomized into a control group and an experimental group who received barefoot training. At pre-test and post-test, all subjects ran at low and high self-selected speeds on a treadmill. Data were collected by systematic observation of lateral and back recordings at 240 Hz. Results McNemar's test indicated significant changes (p < 0.05) in the experimental group at both high and low speed running in foot strike patterns, reducing the percentage of high rearfoot strikers and increasing the number of midfoot strikers. A significant increase (p < 0.05) of external rotation of the foot and a decrease of inversion occurred at comfortable speed in the experimental group. Conclusion Twelve weeks of barefoot running, applied progressively, causes significant changes in foot strike pattern with a tendency toward midfoot or forefoot strikes, regardless of running speed and significant changes in foot rotation at low speed, while the inversion was reduced in left foot at low speed with a tendency toward centered strike.


      PubDate: 2016-01-15T20:48:41Z
       
  • A history of low back pain affects pelvis and trunk coordination during a
           sustained manual materials handling task

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Joseph F. Seay, Shane G. Sauer, Tejash Patel, Tanja C. Roy
      Purpose The purpose of this study was to compare the coordination between the trunk and the pelvis during a sustained asymmetric repetitive lifting task between a group with a history of low back pain (HBP) and a group with no history of LBP (NBP). Methods Volunteers lifted a 11-kg box from ankle height in front to a shelf 45° off-center at waist height, and lowered it to the start position at 12 cycles/min for 10 min. Lifting side was alternated during the trial. Continuous relative phase was used to calculate coordination between the pelvis and trunk rotation at the beginning (Min 1), middle (Min 5), and end of the bout (Min 9). Results While there were no main effects for group, a significant interaction between time and group indicated that, in the frontal plane, the NBP group coordination was more anti-phase toward the end of the bout, with no such differences for the HBP group. Analysis of sagittal-axial (bend and twist) coordination revealed the HBP group coordination was more in-phase at the end of the bout over the entire cycle and for the lifting phase alone, with no such differences for the NBP group. Conclusion Differences between groups demonstrate residual consequences of LBP in an occupational scenario, even though the HBP group was pain-free for >6 months prior to data collection. More in-phase coordination in the HBP group may represent a coordination pattern analogous to “guarded gait” which has been observed in other studies, and may lend insight as to why these individuals are at increased risk for re-injury.


      PubDate: 2016-01-15T20:48:41Z
       
  • Athletes who train on unstable compared to stable surfaces exhibit unique
           postural control strategies in response to balance perturbations

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): D.S. Blaise Williams, Nicholas G. Murray, Douglas W. Powell
      Background Athletes have been shown to exhibit better balance compared to non-athletes. However, few studies have investigated how the surface on which athletes train affects the strategies adopted to maintain balance. Two distinct athlete groups who experience different types of sport-specific balance training are stable surface athletes (SSA) such as basketball players and those who train on unstable surfaces (USA) such as surfers. The purpose of this study was to investigate the effects of training surface on dynamic balance in athletes compared to non-athletes (NON). Methods Eight NON, eight SSA, and eight USA performed five 20-s trials in each of five experimental conditions including a static condition and four dynamic conditions in which the support surface translated in the anteroposterior (AP) or mediolateral (ML) planes using positive or negative feedback paradigms. Approximate entropy (ApEn) and root mean square distance (RMS) of the center of pressure were calculated for the AP and ML directions. Four 3 × 5 (group by condition) repeated measures ANOVAs were used to determine significant effects of group and condition on variables of interest. Results USA exhibited smaller ApEn values than SSA in the AP signals while no significant differences were observed in the ML center of pressure (CoP) signals. Generally, the negative feedback conditions were associated with significantly greater RMS values than the positive feedback conditions. Conclusion USA exhibit unique postural strategies compared to SSA. These unique strategies seemingly exhibit a direction-specific attribute and may be associated with divergent motor control strategies.


      PubDate: 2016-01-15T20:48:41Z
       
  • The effects of total ankle replacement on ankle joint mechanics during
           walking

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Henry Wang, Scott Brown
      Background End-stage ankle arthritis impairs joint function and patients' mobility. Total ankle replacement is a surgical procedure to treat severe ankle arthritis. Salto Talaris Anatomic AnkleTM (STAA) was designed to mimic the normal ankle anatomy and flexion/extension of the ankle movement. The purpose of this study was to examine the effect of an STAA ankle replacement on ankle joint function and mechanics during gait. Methods Five patients with end-stage unilateral ankle arthritis were recruited. Patients performed level walking in a laboratory setting on two occasions, prior to and 3 months after the STAA ankle surgeries. American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score was obtained. A 12-camera motion capture system was used to perform walking analysis. Gait temporo-spatial parameters and ankle joint mechanics were evaluated. Paired Student's t tests and non-parametric Wilcoxon matched tests were performed to examine the differences in biomechanical variables between the pre- and post-surgery walking conditions. Results Compared to the pre-surgical condition, at 3 months of post STAA surgery, patients experienced greater improvement in AOFAS hindfoot score (p = 0.0001); the STAA ankle demonstrated a 31% increase in ankle joint excursion (p = 0.045), a 22% increase in ankle plantarflexor moment (p = 0.075), a 60% increase in ankle power absorption (p = 0.023), and a 68% increase in ankle power production (p = 0.039). Patients also demonstrated a 23% increase in walking speed (p = 0.005), a 20% increase in stride length (p = 0.013), a 15% decrease in double support time (p = 0.043), and a 5% decrease in total stance time (p = 0.055). Conclusion Three months after surgeries, the STAA patients experienced improvements in ankle function and gait parameters. The STAA ankle demonstrated improved ankle mechanics during daily activities such as walking.


      PubDate: 2016-01-15T20:48:41Z
       
  • Non-linearity in the dynamic world of human movement

    • Abstract: Publication date: Available online 6 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Li Li



      PubDate: 2016-01-10T18:46:48Z
       
  • Effects of music and video on perceived exertion during high-intensity
           exercise

    • Abstract: Publication date: Available online 5 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Enoch C. Chow, Jennifer L. Etnier
      Background Dissociative attentional stimuli (e.g., music, video) are effective in decreasing ratings of perceived exertion (RPE) during low-to-moderate intensity exercise, but have inconsistent results during exercise at higher intensity. The purpose of this study was to assess attentional focus and RPE during high-intensity exercise as a function of being exposed to music, video, both (music and video), or a no-treatment control condition. Methods During the first session, healthy men (n = 15) completed a maximal fitness test to determine the workload necessary for high-intensity exercise (operationalized as 125% ventilatory threshold) to be performed during subsequent sessions. On four subsequent days, they completed 20 min of high-intensity exercise in a no-treatment control condition or while listening to music, watching a video, or both. Attentional focus, RPE, heart rate, and distance covered were measured every 4 min during the exercise. Results Music and video in combination resulted in significantly lower RPE across time (partial η 2 = 0.36) and the size of the effect increased over time (partial η 2 = 0.14). Additionally, music and video in combination resulted in a significantly more dissociative focus than the other conditions (partial η 2 = 0.29). Conclusion Music and video in combination may result in lower perceived exertion during high-intensity exercise when compared to music or video in isolation. Future research will be necessary to test if reductions in perceived exertion in response to dissociative attentional stimuli have implications for exercise adherence.


      PubDate: 2016-01-05T18:04:07Z
       
  • Evaluation of the test–retest repeatability of the Injury Severity
           Perception score in patients with acute whiplash-associated disorder

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Robert Ferrari
      Objective To determine the test–retest repeatability of the Injury Severity Perception (ISP) score in participants with acute whiplash-associated disorders (WADs). Methods Consecutive patients with WAD, presenting in the acute stage to a primary care center, were asked to complete the ISP score. ISP was measured with a numerical rating scale that ranged from 0 to 10, on which subjects were asked to rate how severe (in terms of damage) they thought their injury was. The anchors were labeled ‘‘no damage’’ (0) and ‘‘severe, and maybe permanent damage” (10). The ISP questionnaire was administered to the participants at the time of recruitment and again 7 days later. Repeatability was evaluated by calculating percentage agreement and Cohen kappa statistic between the two time points of measurement. Results A total of 94 subjects (34 males, 60 females, mean age 40.6 ± 10.0 years, range 19–60 years) were included. The mean ISP score was 4.9 ± 1.7 (range 2–9 out of 10) at the time of recruitment and 5.1 ± 2.1 (range 2–9 out of 10) 7 days later. The percentage agreement between the two repeat measures of the ISP was 86% and the kappa coefficient was 0.79. Conclusion This study suggests that the test–retest repeatability for the ISP is high and that it is thus likely to have a low risk of classification bias in prognostic studies. The ISP likely has adequate reliability for use in epidemiological research of WADs.


      PubDate: 2015-12-26T13:59:24Z
       
  • Stride length–velocity relationship during running with body weight
           support

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): John A. Mercer, Carmen Chona
      Background Lower body positive pressure (LBPP) treadmills can be used in rehabilitation programs and/or to supplement run mileage in healthy runners by reducing the effective body weight and impact associated with running. The purpose of this study is to determine if body weight support influences the stride length (SL)–velocity as well as leg impact acceleration relationship during running. Methods Subjects (n = 10, 21.4 ± 2.0 years, 72.4 ± 10.3 kg, 1.76 ± 0.09 m) completed 16 run conditions consisting of specific body weight support and velocity combinations. Velocities tested were 100%, 110%, 120%, and 130% of the preferred velocity (2.75 ± 0.36 m/s). Body weight support conditions consisted of 0, 60%, 70%, and 80% body weight support. SL and leg impact accelerations were determined using a light-weight accelerometer mounted on the surface of the anterior-distal aspect of the tibia. A 4 × 4 (velocity × body weight support) repeated measures ANOVA was used for each dependent variable (α = 0.05). Results Neither SL nor leg impact acceleration were influenced by the interaction of body weight support and velocity (p > 0.05). SL was least during no body weight support (p < 0.05) but not different between 60%, 70%, and 80% support (p > 0.05). Leg impact acceleration was greatest during no body weight support (p < 0.05) but not different between 60%, 70%, and 80% support (p > 0.05). SL and leg impact accelerations increased with velocity regardless of support (p < 0.05). Conclusion The relationships between SL and leg impact accelerations with velocity were not influenced by body weight support.


      PubDate: 2015-12-26T13:59:24Z
       
  • Effect of a combined inversion and plantarflexion surface on ankle
           kinematics and EMG activities in landing

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Divya Bhaskaran, Michael Wortley, Qingjian Chen, Clare E. Milner, Eugene C. Fitzhugh, Songning Zhang
      Purpose The purpose of this study was to examine the effects of landing on a combined inversion and plantarflexion surface on the ankle kinematics and electromyographic (EMG) activities of medial gastrocnemius (MG), peroneus longus (PL), and tibialis anterior (TA) muscles. Methods Twelve recreational athletes performed five drop landings from an overhead bar of 30 cm height on to three surfaces: a flat surface, a 25° inversion surface, and a combined surface of 25° inversion and 25° plantarflexion. The kinematic variables and integrated EMG (IEMG) of the three muscles were assessed using a one-way repeated measures ANOVA and a 3 × 3 (surface × muscle) ANOVA, respectively (p < 0.05). Results The IEMG results showed a significant muscle by surface interaction. The flat surface induced higher TA activity than the two tilted surfaces. The inverted surface produced significantly higher inversion peak angle and velocity than the flat surface, but similar PL activity across the surfaces. The MG IEMG, ankle plantarflexion angle, and inversion range of motion were significantly higher for the combined surface compared to the inverted surface. Conclusion These findings suggest that compared to the inversion surface, the combined plantarflexion and inversion surface seems to provide a more unstable surface condition for lateral ankle sprains during landing.


      PubDate: 2015-12-26T13:59:24Z
       
  • Daily heart rate variability of Paralympic gold medallist swimmers: A
           17-week investigation

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Rohan Edmonds, Anthony Leicht, Mark McKean, Brendan Burkett
      Objectives Heart rate variability (HRV) can be a simple, non-invasive method of gauging cardiac autonomic nervous system fluctuations across periodised training workloads and taper in elite athlete populations. The purpose of these three case studies was to examine daily cardiac autonomic variations in Paralympic athletes leading in to the Paralympic games. Methods Three Paralympic gold medallist swimmers were monitored daily for their resting HRV over a 17-week monitoring period leading up to the Paralympic games. Specific time- and frequency-domain measures, along with non-linear indices of HRV were calculated for all analyses. All HRV data were analysed individually using daily values, weekly average values, and average values for rest and training phases. Results A significant difference in HRV was seen for all variables between athlete 1 and athletes 2 and 3 (amputee disabilities) during the entire monitoring period. Conclusion Despite minimal long-term changes, both swimming classification and disability type significantly influence HRV during athlete monitoring. An increased understanding of individual responses to training, travel, and other outside influences affecting Paralympic athletes could potentially lead to improved management and monitoring of training workloads for enhanced performance.


      PubDate: 2015-12-26T13:59:24Z
       
  • Effect of different stretching strategies on the kinetics of vertical
           jumping in female volleyball athletes

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Nicholas T. Kruse, Marcus W. Barr, Roger M. Gilders, Michael R. Kushnick, Sharon R. Rana
      Purpose The present study aimed to examine the effect of static stretching (SS) and a sport-specific dynamic stretching (DS) session at two specific post-stretch time intervals in highly trained female athletes (age 19.90 ± 1.60 years; height 1.80 ± 0.06 m; mass 76.87 ± 9.95 kg) on kinetic parameters of peak force, time-to-takeoff, and rate of force development. Methods The data were collected over 3 days (randomized within subject design with control session). Following each stretch session (SS vs. DS vs. control) of equal duration (7 min total: 30 s per targeted muscle group) participants performed countermovement jumping on a force platform at 1 and 15 min after stretching. Results The DS session significantly improved upon kinetic variables of rate of force development, peak force, and time-to-takeoff relative to SS at 1 min after stretching. No significant effect was found at 15 min. Conclusion Together these findings suggest that when training and competing to jump quickly and maximally the female athlete should incorporate DS instead of SS as part of their pre-competition warm-up, but conduct performance within 15 min of their warm-up to elicit maximal gains.


      PubDate: 2015-12-26T13:59:24Z
       
  • The effects of fluid loss on physical performance: A critical review

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Andrew Carlton, Robin Marc Orr
      Purpose The purpose of this review was to critically analyse the current evidence investigating the effect of an athlete's hydration status on physical performance. Methods A literature search of multiple databases was used to identify studies that met the inclusion criteria for this review. The included studies were then critically appraised using the Downs and Black protocol. Results Nine articles were found to meet the inclusion criteria, with an average score of 79% for methodological quality representative of a “high” standard of research. Conclusion The evidence suggests that dehydration has a negative impact on physical performance for activities lasting more than 30 s in duration. However dehydration was found to have no significant impact on physical performance for activities lasting less than 15 s in duration.


      PubDate: 2015-12-26T13:59:24Z
       
  • The relationship between steeplechase hurdle economy, mechanics, and
           performance

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Sarah Earl, Iain Hunter, Gary W. Mack, Matthew Seeley
      Background Research surrounding the steeplechase is scarce, with most research focusing primarily on how biomechanical factors relate to maintaining running speed while crossing barriers. One area that has not been well explored is the relationship between biomechanical factors and hurdling economy. The purpose of this study was to investigate how performance times and biomechanical variables relate to hurdling economy during the steeplechase. Methods This was accomplished by measuring running economy of collegiate and professional steeplechasers while running with and without hurdles. Biomechanical measures of approach velocity, takeoff distance, clearance height, and lead knee extension while hurdling, as well as steeplechase performance times were correlated to a ratio of running economy with and without hurdles. Results While oxygen uptake was 2.6% greater for the laps requiring five barriers, there was no correlation between steeplechase performance time and the ratio of running economy during the hurdle and non-hurdle laps. Results also indicated no correlation between the aforementioned biomechanical variables and ratio of running economy during the hurdle and non-hurdle laps. Conclusion Increasing approach velocity did not negatively affect running economy. Increased approach velocity is a benefit for maintenance of race pace, but does not hurt economy of movement.


      PubDate: 2015-12-26T13:59:24Z
       
  • Effect of approach run velocity on the optimal performance of the triple
           jump

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Hui Liu, Dewei Mao, Bing Yu
      Purpose The purpose of this study was to determine the effect of horizontal and vertical velocities at the landing of the last step of approach run on the performance and optimal phase ratio of the triple jump. Methods Three-dimensional kinematic data of 13 elite male triple jumpers were obtained during a competition. Computer simulations were performed using a biomechanical model of the triple jump to determine the longest actual distance using the optimal phase ratio with altered horizontal and vertical velocities at the landing of the last step of approach run. Results The actual distance obtained using the optimal phase ratio significantly increased as the horizontal velocity at the landing of the last step of approach run increased (p = 0.001) and the corresponding downward vertical velocity decreased (p = 0.001). Increasing horizontal velocity at the landing of the last step of approach run decreased optimal hop percentage and increased optimal jump percentage (p = 0.001), while decreasing corresponding downward vertical velocity increased optimal hop percentage and decreased optimal jump percentage (p = 0.001). Conclusion The effects of the velocities at the landing of the last step of approach run on the optimal phase ratio were generally small and did not qualitatively alter optimal techniques.


      PubDate: 2015-12-26T13:59:24Z
       
  • The training process: Planning for strength–power training in track
           and field. Part 1: Theoretical aspects

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Brad H. DeWeese, Guy Hornsby, Meg Stone, Michael H. Stone
      The process of strength–power training and the subsequent adaptation is a multi-factorial process. These factors range from the genetics and morphological characteristics of the athlete to how a coach selects, orders, and doses exercises and loading patterns. Consequently, adaptation from these training factors may largely relate to the mode of delivery, in other words, programming tactics. There is strong evidence that the manner and phases in which training is presented to the athlete can make a profound difference in performance outcome. This discussion deals primarily with block periodization concepts and associated methods of programming for strength–power training within track and field.


      PubDate: 2015-12-26T13:59:24Z
       
  • The training process: Planning for strength–power training in track
           and field. Part 2: Practical and applied aspects

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4
      Author(s): Brad H. DeWeese, Guy Hornsby, Meg Stone, Michael H. Stone
      Planning training programs for strength–power track and field athletes require an understanding of both training principles and training theory. The training principles are overload, variation, and specificity. Each of these principles must be incorporated into an appropriate system of training. Conceptually, periodization embraces training principles and offers advantages in planning, allowing for logical integration and manipulation of training variables such as exercise selection, intensification, and volume factors. The adaptation and progress of the athlete is to a large extent directly related to the ability of the coach/athlete to create and carry an efficient and efficacious training process. This ability includes: an understanding of how exercises affect physiological and performance adaptation (i.e., maximum force, rate of force development, power, etc.), how to optimize transfer of training effect ensuring that training exercises have maximum potential for carryover to performance, and how to implement programs with variations at appropriate levels (macro, meso, and micro) such that fatigue management is enhanced and performance progress is optimized.


      PubDate: 2015-12-26T13:59:24Z
       
  • Editorial board

    • Abstract: Publication date: December 2015
      Source:Journal of Sport and Health Science, Volume 4, Issue 4




      PubDate: 2015-12-26T13:59:24Z
       
  • Mental training can improve physical activity behavior in adolescent girls

    • Abstract: Publication date: Available online 24 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Mahboubeh Ghayour Najafabadi, Amir-Hossein Memari, Ramin Kordi, Monir Shayestehfar, Mohammad-Ali Eshghi
      Purpose Lately, physical activity has been frequently discussed in young girls, thus we were interested to examine whether a mental training intervention can increase the level of physical activity in young girls. Methods A sample of 56 girls aged 15.4 0.3 years (mean SD) were assigned to either the intervention or control group. We then conducted a 6-week mental imagery training program on young female participants. Physical activity was evaluated with objective accelometer monitors. Physical self-concept was also assessed in all participants. Results Young females' physical activity increased after a course of mental training compared to female participants in control group. Furthermore physical self-concept improved related to mental training program. Conclusion Exercise imagery may be an effective method of physical activity increase besides psychological enhancement in young girls.


      PubDate: 2015-12-26T13:59:24Z
       
  • Modelling home advantage for individual teams in UEFA Champions League
           football

    • Abstract: Publication date: Available online 24 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Chris Goumas
      Background Home advantage (HA) is well documented in a wide range of team sports including association football (soccer). Although much attention has been paid to differences in the overall magnitude of HA between football competitions and across time, few studies have investigated HA at the team level. Methods A novel method of estimating HA for individual teams, based solely on home performance, was used to compare HA between the highest performing teams and countries in the Union of European Football Associations (UEFA) Champions League over a 10-year period (2003/04 to 2012/13). Away disadvantage (AD) was also estimated based on each team's performance away from home. Poisson regression analysis was used to estimate covariate adjusted HA and AD in terms of the percentage of goals scored at home (HA) and conceded away from home (AD). Results When controlling for differences in team ability, HA did not vary significantly between the 13 selected teams. There was evidence (p < 0.1), however, of between-team variation in AD, ranging from 45% (away advantage) to 68% (away disadvantage). When teams were grouped into the 11 selected countries, both HA and AD varied significantly (p < 0.02) between countries: HA ranged from 52% for Turkish teams to 70% for English teams, while AD ranged from 52% (France) to 67% (Turkey). Conclusion Differences in style of play and tactical approaches to home and away matches may explain some of the variation in HA and AD between teams from different countries.


      PubDate: 2015-12-26T13:59:24Z
       
  • Dual-frequency whole body vibration enhances vertical jumping and
           change-of-direction ability in rugby players

    • Abstract: Publication date: Available online 24 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Wen-Wen Yang, Li-Wei Chou, Wei-Han Chen, Tzyy-Yuang Shiang, Chiang Liu
      Background Traditional vertical and side-alternating whole body vibrations (WBV) can effectively improve muscle power performance but have a limited efficacy for enhancing change-of-direction (COD) ability. Novel dual-plate WBV uniquely providing various directions of movements with higher and distinctive frequencies for each leg, may cause better acute effect on muscle power and SSC efficacy contributing to COD ability. Therefore, the purpose of this study was to investigate the acute effect of dual- or single-frequency WBV on squat jumps (SJs), countermovement jumps (CMJs), eccentric utilization ratios (EURs), and COD ability in rugby players. Methods Fourteen male rugby players were recruited and performed a 4-min partial squat with three types of WBV protocols on a dual-plate WBV machine, including one dual-frequency WBV protocol (DFW) with the dominant leg receiving 35 Hz and the non-dominant leg receiving 45 Hz, and two single-frequency WBV protocols (SFWs) with 35 Hz or 45 Hz provided to both legs (SFW35Hz and SFW45Hz) on three different days. Results The results showed that all the vibration protocols significantly improved SJ and CMJ performances (SJ: p = 0.008; CMJ: p < 0.001), but did not significantly change EURs (p > 0.05). In addition, only the DFW significantly improved COD ability (p = 0.001). Conclusion A 4-min dual-frequency WBV session improved both vertical jumping and COD ability in rugby players, suggesting that this could be a potential warm-up protocol for athletes.


      PubDate: 2015-12-26T13:59:24Z
       
  • Comparison of the effects of cold water and ice ingestion on endurance
           cycling capacity in the heat

    • Abstract: Publication date: Available online 17 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Takashi Naito, Tetsuro Ogaki
      Purpose The purpose of this study was to examine the effects of pre-cooling and fluid replacement with either crushed ice or cold water. Methods On two separate occasions, in a counterbalanced order, nine recreationally-trained males ingested 1.25 g/kg (80–100 g) of either crushed ice (0.5°C) or cold water (4°C) every 5 min for 30 min before exercise. They also ingested 2.0 g/kg (130–160 g) of the same treatment drink at 15, 30, and 45 min after the commencement of cycling to exhaustion at 60%VO2max until voluntary exhaustion in a hot environment (35°C and 30% relative humidity). Results The cycling time to exhaustion in the crushed ice trial (50.0 ± 12.2 min) was longer than the cold water trial (42.2 ± 10.1 min; p = 0.02). Although the rectal temperature fell by 0.37 ± 0.03°C (p = 0.01) at the end of the resting period after the crushed ice ingestion, the rates of rise in rectal temperature during the exercise period were not significantly different between these two conditions (crushed ice: 0.23 ± 0.07°C 5 min; cold water: 0.22 ± 0.07°C 5 min; p = 0.94). Conclusion Crushed ice ingestion before and during exercise in a hot environment may be a preferred and effective approach for minimizing thermal strain, and for improving endurance performance as compared with cold water ingestion.


      PubDate: 2015-12-21T13:36:24Z
       
  • Children's expectancy beliefs and subjective task values through two years
           of school-based program and associated links to physical education
           enjoyment and physical activity

    • Abstract: Publication date: Available online 15 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Arto Gråstén
      Purpose The present study examined the patterns of children's expectancy beliefs and subjective task values through the Physical Activity as Civil Skill Program and associated links to physical education enjoyment, total physical activity. Methods The sample comprised 401 children aged 9 to 13 years from three small towns located in North-East Finland. All children received school-based activities across 2-year program from Grades 5 to 7. The present data were collected using questionnaires across three measurement phases during 2012 - 2014. Results The levels of expectancy beliefs and subjective task values indicated to be relatively high and the development was stable through the program, especially in terms of expectancy beliefs, attainment value, and cost. In contrast, interest value and utility value decreased over the particular period of time. Boys believed they are physically more competent when compared to other students and valued physical education classes more important than girls. In addition, the higher physical activity level the children reported, the higher physical education enjoyment they perceived. Conclusion The current program including actions to increase physical activity through manipulation of psychological and physical school environment modifications indicated to be an effective strategy to prohibit declining levels of children's expectancy beliefs and task values.


      PubDate: 2015-12-16T15:07:24Z
       
  • Immersible ergocycle prescription as a function of relative exercise
           intensity

    • Abstract: Publication date: Available online 14 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Mauricio Garzon, Mathieu Gayda, Anil Nigam, Alain-Steve Comtois, Martin Juneau
      Purpose The purpose of this study was to establish the relationship between various expressions of relative exercise intensity (%VO2max, %HRmax, %VO2 reserve (%VO2R), and %HR reserve (%HRR)) in order to obtain the more appropriate method for exercise intensity prescription when using an immersible ergocycle (IE) and to propose a prediction equation to estimateVO2max based on IE pedalling rate (rpm) for individualized exercise training prescription. Methods Thirty-three healthy participants performed incremental exercise tests on IE and dryland ergocycle (DE) at equal external power output (Pext). Exercise on IE began at 40 rpm and was increased by 10 rpm until exhaustion. Exercise on DE began with an initial load of 25 W and increased by 25 W/min until exhaustion. VO2was measured with a portable gas analyser (COSMED K4b2) during both incremental tests. On IE and DE, %VO2R, %HRmax and %HRR at equal Pext did not differ (p > 0.05). Results The %HRR vs. %VO2R regression for both IE and DE did not differ from the identity line (%VO2R: IE = 0.988 % × HRR + 0.009, r 2 = 0.91, SEE: 11%; %VO2R: DE = 0.944 % × HRR + 0.013, r 2 = 0.94, SEE: 8%). Similar mean values for %HRmax, %VO2R and %HRR at equal Pext were observed on IE and DE. PredictedVO2 obtained according to rpm on IE is represented by: VO2 (L/min) = 0.000542 × rpm2 - 0.026 × rpm + 0.739 (r = 0.91, SEE = 0.319 L/min). Conclusion The %HRR – %VO2R relationship appears to be the most accurate for exercise training prescription on IE. This study offers news tools to better prescribe, control and individualize exercise intensity on IE.


      PubDate: 2015-12-16T15:07:24Z
       
  • Tribulus terrestris extracts alleviate muscle damage and promote anaerobic
           performance of trained male boxers and its mechanisms: Roles of androgen,
           IGF-1 and IGF binding protein-3

    • Abstract: Publication date: Available online 14 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Yiming Ma, Zhicheng Guo, Xiaohui Wang
      Purpose To investigate the effects of Tribulus terrestris (TT) extracts on muscle mass, muscle damage, and anaerobic performances of trained male boxers and its mechanisms: roles of plasma androgen, IGF-1, and IGF-1 binding protein-3 (IGFBP-3). Methods Fifteen male boxers were divided into exercise group (E, n = 7) and exercise plus TT group (E + TT, n = 8). The two groups both undertook 3-week high intensity and 3-week high volume trainings separated by a 4-week rest. TT extracts (1,250 mg/day) were orally administered by boxers in E + TT group. TT extract compositions were detected by UHPLC–Q-TOF/MS. Before and at the end of the two trainings, muscle mass, anaerobic performance, and blood indicators were explored. Results Compared with E group, decreases of plasma CK (1,591.50 ± 909.55 vs. 2,719.86 ± 832.47 U/L) and IGFBP-3 (3,075.53 ± 1,072.45 vs. 3,950.83 ± 479.25 ng/mL) as well as increases of mean power (MP, 459.42 ± 122.25 vs. 434.60 ± 69.47 W) and MP/body weight (MP/BW, 7.54 ± 0.85 vs. 7.07 ± 1.09 W/kg) were detected in E + TT group after a high intensity training. For high volume training, reduction of IGFBP-3 (2,946.38 ± 974.07 vs. 3,632.67 ± 470.06 ng/mL) and increases of MP (508.71 ± 103.21 vs. 477.81 ± 49.90 W) and MP/BW (8.24 ± 0.29 vs. 7.52 ± 0.92 W/kg) were detected in E + TT group. Muscle mass, blood levels of testosterone, dihydrotestosterone (DHT), and IGF-1 were unchanged between the two groups. Conclusion Taking 1,250 mg capsules containing TT extracts did not change muscle mass and plasma levels of testosterone, DHT, and IGF-1 but significantly alleviated muscle damage and promoted anaerobic performance of trained male boxers, which may be related to the decrease of plasma IGFBP-3 rather than androgen in plasma.


      PubDate: 2015-12-16T15:07:24Z
       
  • Shock attenuation, spatio-temporal and physiological parameter comparisons
           between land treadmill and water treadmill running

    • Abstract: Publication date: Available online 15 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Paul W. Macdermid, Philip W. Fink, Stephen Stannard
      Purpose The purpose of this study was to compare shock attenuation, spatio-temporal and physiological parameters during water immersed (depth: anterior superior iliac spine) treadmill running (ATM) and land based treadmill running (LTM), matched for speed. Methods Six participants completed 15 min running under two conditions (LTM and ATM) in a randomized and balanced order, matched for speed. Synchronised tri-axial accelerometers placed at the distal tibia, lumbar region, and forehead were used to identify running dynamics and measure acceleration on impact and its attenuation. Expired respiratory gases and heart rate were sampled on a breath-by-breath basis for physiological variable collection throughout each trial. Results Participants experienced reduced accelerations on impact at the distal tibia (p < 0.0001) but not the lower back or forehead (p = 0.1363) during ATM compared to LTM. Consequently, large reductions (p = 0.0001) in shock attenuation occurred during the ATM compared to LTM. Stride frequency was greater (p < 0.0001) and stride length shorter (p < 0.0001) as a result of reduced swing time (p < 0.0001) for LTM, while ATM running increased (p < 0.0001) physiological demand for both heart rate and O2 compared to LTM. Conclusion These findings show ATM reduces impact stress on the passive structures of the lower limbs whilst increasing physiological demand when running at matched speeds.


      PubDate: 2015-12-16T15:07:24Z
       
  • Assessing acceptance in mindfulness with direct-worded items: The
           development and initial validation of the athlete mindfulness
           questionnaire

    • Abstract: Publication date: Available online 14 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Chun-Qing Zhang, Pak-Kwong Chung, Gangyan Si
      Purpose The purpose of the current study was to develop and validate a sport-specific mindfulness measure, the Athlete Mindfulness Questionnaire (AMQ), through five related studies using four separate samples of Chinese athletes. The AMQ is a 3-factor measure designed to assess mindfulness that reflects present-moment attention, awareness, and acceptance in a sport context. Methods In Study 1, an initial pool of items was generated based on previous literature, existing mindfulness scales, as well as interviews with and feedback from the athletes, coaches, and mindfulness experts. Initial support for the 3-factor structure of the AMQ was established via exploratory factor analysis in Study 2, and cross-validated through confirmatory factor analysis in Studies 3 and 4. In Study 5, a modified 3-factor AMQ with direct-worded acceptance items was examined in a fourth independent sample. Results Convergent and concurrent validities of the acceptance subscale failed to be established in Studies 3 and 4 which may be due to the inattention and confusion of the athletes whilst interpreting the reverse-worded items. A modified 16-item AMQ in Study 5 displayed satisfactory model fit and acceptable internal consistencies. Most importantly, convergent and concurrent validities of the 16-item AMQ were supported. The three subscales showed significant positive associations with mindfulness, flow, well-being, and positive affect, and significant negative associations with experiential avoidance, burnout and negative affect. Conclusion The AMQ is a psychometrically sound measure of mindfulness in a sport context. The importance of using direct-worded acceptance items is discussed.


      PubDate: 2015-12-16T15:07:24Z
       
  • Validity and reliability of three methods of stiffness assessment

    • Abstract: Publication date: Available online 8 December 2015
      Source:Journal of Sport and Health Science
      Author(s): Elizabeth C. Pruyn, Mark L. Watsford, Aron J. Murphy
      Background Stiffness is commonly assessed in relation to injury and athletic performance. The purpose of this research was to compare the validity and reliability of three in-vivo methods of stiffness assessment using one cohort of participants. Methods To determine inter-day reliability, 15 female netballers were assessed for stiffness twice within 1 week using unilateral hopping (vertical stiffness), free oscillations of the calf and myometry of various muscles of the triceps surae. To establish convergent construct validity, stiffness was compared to static and dynamic strength measurements. Results Test–retest stiffness results revealed that vertical stiffness produced moderate to high reliability results and myometry presented moderate to very high reliability. In contrast, the free oscillation technique displayed low to moderate reliability. Vertical stiffness demonstrated a significant correlation with rate of force development during a squat jump, whilst myometer stiffness measurements from three sites in the lower limb revealed significant correlations with isometric rate of force development. Further, significant negative correlations were evident between the eccentric utilisation ratio and various myometer stiffness results. No relationships were established between the free oscillation technique and any of the performance measurements. Conclusion These results suggest that vertical stiffness and myometry are valid and reliable methods for assessing stiffness.


      PubDate: 2015-12-11T17:59:12Z
       
  • Acknowledgment to reviewers – November 2014 to October 2015

    • Abstract: Publication date: Available online 29 October 2015
      Source:Journal of Sport and Health Science




      PubDate: 2015-11-02T04:39:34Z
       
  • Scientific research on track and field

    • Abstract: Publication date: Available online 8 October 2015
      Source:Journal of Sport and Health Science
      Author(s): Bing Yu



      PubDate: 2015-10-11T06:37:04Z
       
  • Integrating biomechanical and motor control principles in elite high
           jumpers: A transdisciplinary approach to enhancing sport performance

    • Abstract: Publication date: Available online 25 September 2015
      Source:Journal of Sport and Health Science
      Author(s): James Becker, Will F.W. Wu
      Background In recent years, there has been a proliferation of technology and sport science utilized within an athlete's training, especially at the elite level. However, the sport science is a broad field, encompassing disciplines such as biomechanics, motor control and learning, exercise physiology, sports medicine, sport psychology to name a few. Rarely are these disciplines applied in an integrated manner. The purpose of this study was to document the effectiveness of an integrated biomechanics and motor control protocol for improving athlete's performance in the high jump. Methods Four elite high jumpers performed baseline jumps under normal conditions and then jumps using a specific external focus of attention cue designed to improve their running posture. Three-dimensional biomechanical analysis was used to quantify the upright posture throughout the approach as well as horizontal velocity at plant and vertical velocity at takeoff. Results The results showed that when using the external focus of attention cue, the jumpers were significantly more upright during the approach, had significantly higher horizontal velocities at plant, and generated significantly greater vertical velocities during the takeoff. Conclusion The results of this study lay the foundation for future work examining how integrating sport science disciplines can improve performance of elite level athletes.


      PubDate: 2015-09-28T04:15:09Z
       
  • Surface effects on in-shoe plantar pressure and tibial impact during
           running

    • Abstract: Publication date: Available online 2 September 2015
      Source:Journal of Sport and Health Science
      Author(s): Weijie Fu, Ying Fang, David Ming Shuo Liu, Lin Wang, Sicong Ren, Yu Liu
      Purpose This study aims to explore the effects of running on different surfaces on the characteristics of in-shoe plantar pressure and tibial acceleration. Methods Thirteen male recreational runners were required to run at 12 km/h velocity on concrete, synthetic track, natural grass, a normal treadmill, and a treadmill equipped with an ethylene vinyl acetate (EVA) cushioning underlay (treadmill_EVA). An in-shoe plantar pressure system and an accelerometer attached to the tibial tuberosity were used to record and analyze the characteristics of plantar pressure and tibial impact during running. Results The results showed that there were no significant differences in 1st and 2nd peak plantar pressure (time of occurrence), pressure-time integral, and peak pressure distribution for the concrete, synthetic, grass, and normal treadmill surfaces. No significant differences in peak positive acceleration were observed among the five tested surface conditions. Compared to the concrete surface, however, running on treadmill_EVA showed a significant decrease in 1st peak plantar pressure and the pressure-time integral for the impact phase (p < 0.05). These can be further ascribed to a reduced peak pressure observed at heel region (p < 0.05). Conclusion There may not be an inevitable relationship between the surface and the lower-limb impact in runners. It is, however, still noteworthy that the effects of different treadmill surfaces should be considered in the interpretation of plantar pressure performance and translation of such results to overground running.


      PubDate: 2015-09-03T17:26:09Z
       
  • Biomechanical characteristics of an anterior cruciate ligament injury in
           javelin throwing

    • Abstract: Publication date: Available online 22 July 2015
      Source:Journal of Sport and Health Science
      Author(s): Boyi Dai, Min Mao, William E. Garrett, Bing Yu
      Purpose The purpose of this study was to understand the mechanism of an anterior cruciate ligament (ACL) injury in javelin throwing and javelin throwing techniques relevant to this ACL injury. Methods The patient in this study was an elite female javelin thrower who completed the first three trials and sustained a non-contact ACL injury on her left knee in the fourth trial of javelin throwing during a recent track and field meet. Three-dimensional kinematic data were collected in the injury and non-injury trials. The kinematic data of 52 male and 54 female elite javelin throwers were obtained from a javelin throwing biomechanical database. Results The patient had greater forward center of mass velocity and less vertical center of mass velocity after the first 25% of the delivery phase in the injury trial compared to non-injury trials. The patient had less left knee flexion angle and angular velocity but similar left knee valgus and internal rotation angles during the first 21% of the delivery phase in the injury trial compared to non-injury trials. The video images showed an obvious tibia anterior translation at the 30% of the delivery phase in the injury trial. The left knee flexion angle and angular velocity at the time of the left foot landing and the maximal left knee flexion angle during the delivery phase were not significantly correlated to the official distance for 52 male and 54 female elite javelin throwers. Conclusion The ACL injury in this study occurred during the first 30% of the delivery phase, most likely during the first 25% of the delivery phase. A stiff landing of the left leg with a small knee flexion angle was the primary contributor to this injury. Javelin throwers may have a soft left leg landing with a flexed knee, which may help them prevent ACL injuries without compromising performance.


      PubDate: 2015-07-28T20:49:52Z
       
  • Hypoxic training methods for improving endurance exercise performance

    • Abstract: Publication date: Available online 23 July 2015
      Source:Journal of Sport and Health Science
      Author(s): Jacob A. Sinex, Robert F. Chapman
      Endurance athletic performance is highly related to a number of factors that can be altered through altitude and hypoxic training including increases in erythrocyte volume, maximal aerobic exercise capacity, capillary density, and economy. Physiological adaptations in response to acute and chronic exposure to hypoxic environments are well documented and range from short-term detrimental effects to longer-term adaptations that can improve performance at altitude and in sea-level competitions. Many altitude and hypoxic training protocols have been developed, employing various combinations of living and training at sea level, low, moderate, and high altitudes and utilizing natural and artificial altitudes, with varying degrees of effectiveness. Several factors have been identified that are associated with individual responses to hypoxic training, and techniques for identifying those athletes most likely to benefit from hypoxic training continue to be investigated. Exposure to sufficiently high altitude (2,000–3,000 m) for more than 12 h/day, while training at lower altitudes, for a minimum of 21 days is recommended. Timing of altitude training related to competition remains under debate, although general recommendations can be considered.


      PubDate: 2015-07-28T20:49:52Z
       
 
 
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