Kizzi Joseph, Sum Alvin, Houston Fraser E, Hayes Lawrence D
a School of Human Sciences , London Metropolitan University , London , UK.
b Department of Applied Physiology and Kinesiology , University of Florida , Gainesville , FL , USA.
Eur J Sport Sci. 2016 Nov;16(8):1087-94. doi: 10.1080/17461391.2016.1165739. Epub 2016 Mar 28.
Attenuated performance during intense exercise with limited endogenous carbohydrate (CHO) is well documented. Therefore, this study examined whether caffeine (CAF) mouth rinsing would augment performance during repeated sprint cycling in participants with reduced endogenous CHO. Eight recreationally active males (aged 23 ± 2 yr, body mass 84 ± 4 kg, stature 178 ± 7 cm) participated in this randomized, single-blind, repeated-measures crossover investigation. Following familiarization, participants attended two separate evening glycogen depletion sessions. The following morning, participants completed five, 6 s sprints on a cycle ergometer (separated by 24 s active recovery), with mouth rinsing either (1) a placebo solution or (2) a 2% CAF solution. During a fifth visit, participants completed the sprints without prior glycogen depletion. Repeated-measures ANOVA identified significant main effect of condition (CAF, placebo, and control [P < .05; effect size (ES) = 0.850-0.897]), sprint (1-5 [P < .005; ES = 0.871-0.986]), and interaction (condition × sprint [P < .05; ES = 0.831-0.846]), for peak and mean power. The control condition exhibited the highest peak power (overall mean 760 ± 77 W) and mean power (overall mean 699 ± 83W) over the five sprints (P < .001 in both instances). CAF peak power (overall mean 643 ± 79 W) was significantly greater than placebo (mean 573 ± 79 W [P < .05; ES = 0.850]). Additionally, CAF mean power (overall mean 589 ± 80 W) was significantly greater than placebo (519 ± 82 W [P < .05; ES = 0.397]). These data indicate that mouth rinsing a caffeinated solution reduces decrements caused by CHO reduction, which may benefit athletes wishing to train in a low-CHO state.
内源性碳水化合物（CHO）储备有限时剧烈运动表现下降已有充分记录。因此，本研究探讨了对于内源性CHO储备减少的参与者，含漱咖啡因（CAF）是否会提高重复冲刺骑行期间的运动表现。八名有运动习惯的男性（年龄23±2岁，体重84±4千克，身高178±7厘米）参与了这项随机、单盲、重复测量的交叉研究。在熟悉实验流程后，参与者参加了两个单独的夜间糖原耗竭训练。第二天早上，参与者在自行车测力计上完成五次6秒的冲刺（每次冲刺间隔24秒的主动恢复），期间分别含漱（1）安慰剂溶液或（2）2%的CAF溶液。在第五次访视时，参与者在没有预先糖原耗竭的情况下完成冲刺。重复测量方差分析确定了条件（CAF、安慰剂和对照[P<.05；效应大小（ES）=0.850 - 0.897]）、冲刺次数（1 - 5次[P<.005；ES = 0.871 - 0.986]）以及交互作用（条件×冲刺次数[P<.05；ES = 0.831 - 0.846]）对峰值功率和平均功率有显著的主效应。在五次冲刺中，对照条件下的峰值功率最高（总体平均值760±77瓦）和平均功率最高（总体平均值699±83瓦）（两种情况均P<.001）。CAF的峰值功率（总体平均值643±79瓦）显著高于安慰剂（平均值573±79瓦[P<.05；ES = 0.850]）。此外，CAF的平均功率（总体平均值589±80瓦）显著高于安慰剂（519±82瓦[P<.05；ES = 0.397]）。这些数据表明，含漱含咖啡因溶液可减少因CHO减少引起的运动表现下降，这可能对希望在低CHO状态下训练的运动员有益。
