ABSTRACT
This study aimed to investigate the effects of caffeine on performances of simulated match, Wingate Anaerobic Test (WAnT), and cognitive function test of elite taekwondo athletes. Ten elite taekwondo athletes in Hong Kong volunteered to participate in two main trials in a randomized double-blinded crossover design. In each main trial, 1 h after consuming a drink with caffeine (CAF) or a placebo drink without caffeine (PLA), the participants completed two simulated taekwondo match sessions followed by the WAnT. The participants were instructed to complete three cognitive function tests, namely the Eriksen Flanker Test (EFT), Stroop Test, and Rapid Visual Information Processing Test, at baseline, before exercise, and immediately after the simulated matches. They were also required to wear functional near-infrared spectroscopy equipment during these tests. Before exercise, the reaction time in the EFT was shorter in the CAF trial than in the PLA trial (PLA: 494.9 ± 49.2 ms vs. CAF: 467.9 ± 38.0 ms, p = 0.035). In the WAnT, caffeine intake increased the peak power and mean power per unit of body weight (by approximately 13% and 6%, respectively, p = 0.018 & 0.042). The performance in the simulated matches was not affected by caffeine intake (p = 0.168). In conclusion, caffeine intake enhances anaerobic power and may improve certain cognitive functions of elite taekwondo athletes in Hong Kong. However, this may not be enough to improve the simulated match performance.
Subject(s)
Athletic Performance , Caffeine , Anaerobiosis , Athletes , Caffeine/pharmacology , Cognition , Cross-Over Studies , Double-Blind Method , Hong Kong , Humans , PolyestersABSTRACT
BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a common developmental disorder in childhood, with a 5%-6% worldwide prevalence. Children with ADHD often demonstrate impaired executive function, which is closely related to the development of the commonly observed behavioral problems such as inattention, impaired inhibition, and hyperactivity. The purpose of this study is to examine whether a game-based high-intensity interval training (HIIT) program can improve the executive function of children with ADHD, compared with a traditional structured aerobic exercise program and a non-treatment control group. METHODS/DESIGN: A total of 42 children with ADHD will be recruited to participate in this three-arm school-based randomized controlled trial. An 8-week specially designed game-based HIIT (GameHIIT) program and a traditional game-based structured aerobic exercise (GameSAE) program will be delivered to those children randomly assigned to these two intervention groups, while the children in the control group will maintain their regular physical activity over the same period. A number of outcome measures including executive function, cerebral hemodynamic response, physical activity, physical fitness, and enjoyment and adherence to the intervention will be assessed for both groups at baseline (T0), immediately after the intervention period (T1), and after the follow-up period (T2). DISCUSSION: HIIT has recently emerged as a feasible and efficacious strategy for increasing physical health outcomes and cognitive function, including executive function, in healthy young people. However, research has yet to investigate whether the executive function of children with ADHD can be effectively enhanced through HIIT. If, as hypothesized, GameHIIT program improves outcomes for children with ADHD, the present research will inform the development of targeted exercise programs that can be more broadly used with this particular population.
Subject(s)
Attention Deficit Disorder with Hyperactivity , High-Intensity Interval Training , Adolescent , Child , Cognition , Executive Function , Humans , Randomized Controlled Trials as Topic , Treatment OutcomeABSTRACT
BACKGROUND: The previous investigations in diurnal variation of endurance sports performance did not reach a consensus and have been limited. This study would be a valuable resource for endurance sports trainers and event managers to plan their training and competition in a specific time of day. OBJECTIVES: The aim of this study is to find out the diurnal variation in cardiovascular endurance performance in the young athletes. MATERIALS AND METHODS: Thirty five athlete students (15.17 ± 1.62 years) participated in this study. Maximal oxygen uptake (VO2max), post-exercise percentage of maximal heart rate (MHR% post-ex), post-exercise body temperature (BTemppost-ex), and post exercise blood lactic acid level (LApost-ex) were measured in this study. Three non-consecutive testings: A) Morning (09:00-10:00; AM), B) Noon (12:00-13:00; NN) and C) Afternoon (16:00-17:00; PM) were conducted. Participants were required to follow the meal plan and resting schedule for all testing days. RESULTS: VO2max was significantly higher at NN (F2. 68 = 3.29, P < 0.05, η2 = 0.088) in comparison with PM. The MHR%post-ex, BTemppost-ex, LApost-ex was not significantly different among three times of day. CONCLUSIONS: Diurnal effect on endurance performance was found and the highest exercise VO2max was identified at noon. Secondary school students or young athletes are recommended to have sports training related to VO2max at noon for the purpose of maximizing training effectiveness.
