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991.
To determine gender differences, positional differences, and patterns of change in the performance of the basketball line-drill test, 93 male (mean age 16.8 years, s = 1.1) and 95 female (mean age 16.5 years, s = 1.0) basketball players undertook 516 line-drill tests over a 5-year period. Log-transformed performance times were analysed using a mixed model that included quadratic within-participant fixed effects for time in the season and time in the programme. Changes and differences were standardized for interpretation of magnitudes. Mean performance times were 28.0 s (s = 1.3) for males and 30.4 s (s = 1.3) for females. The mean pattern of change in performance within a season differed substantially between the sexes and playing positions: male guards and female centres showed moderate to very large improvements mid-season of 1.1% and 3.5% respectively (90% confidence limits +/-2.1% and +/-3.0%), while female guards and male forwards showed large to very large decrements of -1.6% (+/-2.6%) and -2.4% (+/-2.0%). Over 3 years, males improved performance across all three playing positions by 1.4% (+/-1.3%) and females by 2.9% (+/-1.4%). Males improved performance by 0.2% (+/-0.5%) per year, whereas the performance of females deteriorated by 0.6% (+/-0.4%) per year. The differing patterns of performance change presumably reflect variations in training and competition loads, with short-term fluctuations in performance being managed to promote longer-term improvements. 相似文献
992.
Carbohydrate intake during endurance exercise delays the onset of fatigue and improves performance. Two recent cycling studies have reported increased time to exhaustion when protein is ingested together with carbohydrate. The purpose of the present study was to test the hypothesis that ingestion of a carbohydrate + protein beverage will lead to significant improvements in cycling time-trial performance relative to placebo and carbohydrate alone. Thirteen cyclists completed 120 min of constant-load ergometer cycling. Thereafter, participants performed a time-trial in which they completed a set amount of work (7 kJ kg(-1)) as quickly as possible. Participants completed four experimental trials, the first for familiarization and then three randomized, double-blind treatments consisting of a placebo, carbohydrate, and carbohydrate + protein. Participants received 250 ml of beverage every 15 min during the constant-load ride. Time-trial performance for carbohydrate (37.1 min, s = 3.8) was significantly (P < 0.05) faster than placebo (39.7 min, s = 4.6). Time-trial performance for carbohydrate + protein (38.8 min, s = 5.5) was not significantly different from either placebo or carbohydrate. Ingestion of a carbohydrate beverage during two hours of constant-load cycling significantly enhanced subsequent time-trial performance compared with placebo. The carbohydrate + protein beverage provided no additional performance benefit. 相似文献
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Barr-Anderson DJ Neumark-Sztainer D Schmitz KH Ward DS Conway TL Pratt C Baggett CD Lytle L Pate RR 《Research quarterly for exercise and sport》2008,79(1):18-27
The current study examined associations between physical education (PE) class enjoyment and sociodemographic, personal, and perceived school environment factors among early adolescent girls. Participants included 1,511 sixth-grade girls who completed baseline assessments for the Trial of Activity in Adolescent Girls, with 50% indicating they enjoyed PE class a lot. Variables positively associated with PE class enjoyment included physical activity level, perceived benefits of physical activity, self-efficacy for leisure time physical activity, and perceived school climate for girls' physical activity as influenced by teachers, while body mass index was inversely associated with PE class enjoyment. After adjusting for all variables in the model, PE class enjoyment was significantly greater in Blacks than in Whites. In model testing, with mutual adjustment for all variables, self-efficacy was the strongest correlate of PE class enjoyment, followed by perceived benefits, race/ethnicity, and teachers' support for girls' physical activity, as compared to boys, at school. The overall model explained 11% of the variance in PE class enjoyment. Findings suggest that efforts to enhance girls' self-efficacy and perceived benefits and to provide a supportive PE class environment that promotes gender equality can potentially increase PE class enjoyment among young girls. 相似文献
998.
Grounded in the 2x2 achievement goal framework (Elliot & McGregor, 2001), a model was tested examining the hypothesized relationships between approach and avoidance (mastery and performance) goals, challenge and threat appraisals of sport competition, and positive and negative indices of well-being (i.e., self-esteem, positive, and negative affect). A further aim was to determine the degree to which the cognitive appraisals mediated the relationship between the four achievement goals and the indicators of athletes' welfare. Finally, measurement and structural invariance was tested with respect to gender in the hypothesized model. An alternative model was also estimated specifying self-esteem as an antecedent of the four goals and cognitive appraisals. Four hundred and twenty-four team sport participants (Mage=24.25) responded to a multisection questionnaire. Structural equation modeling analyses provided support for the hypothesized model only. Challenge and threat appraisals partially mediated the relationships observed between mastery-based goals and the well-being indicators. Lastly, the hypothesized model was found to be invariant across gender. 相似文献
999.
为了探讨体育康复方法时于矫正姿势性驼背的效果,选取华东师范大学体育与健康学院03、04、05级的本科学生60名作为研究对象,其年龄在19~23岁之间,随机分为实验组和对照组,实验组同学进行为期3个月的运用体育康复方法进行姿势性驼背的矫正练习,对照组同学不进行姿势性驼背的矫正练习.实验证明,姿势性驼背的体育康复方法不但对于矫正姿势性驼背具有良好的效果,还可提高学生的健康状况. 相似文献
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