Poire Benjamin, Killen Lauren G, Green James M, O'Neal Eric K, Renfroe Lee G
Department of Kinesiology, University of North Alabama, Florence, AL, USA.
Int J Exerc Sci. 2019 Nov 1;12(6):1290-1301. doi: 10.70252/FWBV4767. eCollection 2019.
This study examined the effects of caffeine on tennis serve accuracy. Division II tennis athletes ( = 10) completed two serve trials (double-blind, counterbalanced) following ingestion of 6 mg/kg of caffeine or matched placebo an hour prior to data collection. During each tennis serve trial, participants completed 48 non-fault serves divided into 3 sets with 2 serves per 8 different targets. Following each 2 serves per target format, participants completed a shuttle run sprint. Separate 2 (trial) × 8 (targets) repeated measures analysis of variances (ANOVAs) were used for distances from the target center "delta", and necessary tries for each of the 3 sets. A 2 (treatment) × 3 (set) repeated measures ANOVA was used for shuttle run times. While results were not significant, the treatment main effect approached significance ( = 0.07) in set 2 for the delta of distances when comparing caffeine (96.2 cm ± 19.8) versus placebo (107.1 cm ± 16.3). While there was no significance in sprint times, each sprint was consistently faster following caffeine consumption. Post-trial surveys revealed subjective responses approached significance with greater feelings of stomach distress ( = 0.08) and nervousness ( = 0.13) following caffeine and elevated feeling of fatigue ( = 0.19) following placebo. Therefore, with no impairment in serve accuracy coupled with some evidence of reduced fatigue, results suggest caffeine may benefit tennis athletes. Extending the understanding of the effects of caffeine on tennis serve accuracy and performance could benefit overall match performance, with the potential of improving the match outcome in extended playtime.
本研究考察了咖啡因对网球发球准确性的影响。二级网球运动员(n = 10)在数据收集前一小时摄入6毫克/千克咖啡因或匹配的安慰剂后,完成了两次发球试验(双盲、平衡)。在每次网球发球试验中,参与者完成48次无失误发球,分为3组,每组针对8个不同目标各发2次球。按照每个目标发2次球的模式,参与者完成一次往返跑冲刺。分别对距目标中心的距离“偏差”以及每组的必要发球次数进行2(试验)×8(目标)重复测量方差分析(ANOVA)。对往返跑时间进行2(处理)×3(组)重复测量方差分析。虽然结果不显著,但在比较咖啡因组(96.2厘米±19.8)和安慰剂组(107.1厘米±16.3)时,处理主效应在第2组中对于距离偏差接近显著水平(p = 0.07)。虽然冲刺时间没有显著差异,但每次冲刺在摄入咖啡因后始终更快。试验后的调查显示,主观反应接近显著水平,摄入咖啡因后胃部不适(p = 0.08)和紧张感(p = 0.13)更强,而摄入安慰剂后疲劳感增强(p = 0.19)。因此,在发球准确性没有受损且有一些疲劳减轻的证据的情况下,结果表明咖啡因可能对网球运动员有益。扩展对咖啡因对网球发球准确性和表现影响的理解可能有益于整体比赛表现,有可能在延长的比赛时间内改善比赛结果。