School of Sport, Health and Applied Science, St Mary's University, Twickenham, United Kingdom; and.
School of Science and Technology, University of New England, Armidale, New South Wales, Australia.
J Strength Cond Res. 2020 Dec;34(12):3475-3481. doi: 10.1519/JSC.0000000000002299.
Jeffries, O, Hill, J, Patterson, SD, and Waldron, M. Energy drink doses of caffeine and taurine have a null or negative effect on sprint performance. J Strength Cond Res 34(12): 3475-3481, 2020-This study investigated the effects of caffeine and taurine coingestion on repeat-sprint cycling performance and associated physiological and perceptual responses. In a double-blind, cross-over, repeated measures study, 11 male subjects (age 21 ± 2 years; stature 178 ± 7 cm; body mass 80 ± 13 kg) completed 10 × 6-second sprints on a cycle ergometer, each separated by 24 seconds, one hour after ingesting: caffeine (80 mg) and taurine (1 g), equivalent to the amount observed in popular commercial energy drinks, or placebo (maltodextrin ∼1 g) in a gelatine capsule. Performance was measured on a cycle ergometer, whereas blood lactate concentration (B[la]), rating of perceived exertion (RPE), and heart rate (HR) were measured at baseline (pre-exercise) and after sprints 5 and 10. Magnitude-based inferences revealed likely, trivial differences in peak power and unclear, trivial intersprint fatigue index after ingestion of the caffeine and taurine supplement. Intrasprint fatigue was greater in the caffeine and taurine condition at sprint 10 (likely, small) and possibly smaller in sprints 6-9. The caffeine and taurine supplement had a likely large effect on HR at baseline (effect size = 0.94) and increases in B[la] after sprints 5 (likely small) and 10 (possibly small). There was no effect of the supplement on RPE (unclear, trivial). Administration of caffeine and taurine at doses equivalent to commercial energy drinks did not improve repeat-sprint cycling performance and seemed to induce greater fatigue within selected sprints, particularly at the end of the trial. This undesirable performance effect occurs in parallel with increased HR and glycolytic metabolic bi-products.
杰弗里斯、希尔、帕特森和沃尔德伦。能量饮料中咖啡因和牛磺酸的剂量对短跑表现没有影响或产生负面影响。J 力量与条件研究 34(12):3475-3481,2020 年-本研究调查了咖啡因和牛磺酸共同摄入对重复冲刺自行车性能及相关生理和感知反应的影响。在一项双盲、交叉、重复测量的研究中,11 名男性受试者(年龄 21 ± 2 岁;身高 178 ± 7cm;体重 80 ± 13kg)在一小时后服用:咖啡因(80mg)和牛磺酸(1g),相当于流行商业能量饮料中的含量,或明胶胶囊中的安慰剂(麦芽糊精约 1g),进行 10 次 6 秒冲刺的自行车测力计,每次冲刺间隔 24 秒。在基线(运动前)和冲刺 5 次和 10 次后测量运动表现,同时测量血乳酸浓度(B[la])、感知用力程度(RPE)和心率(HR)。基于幅度的推断表明,摄入咖啡因和牛磺酸补充剂后,峰值功率可能存在微小差异,冲刺间疲劳指数不太清楚且微小。冲刺 10 次时,咖啡因和牛磺酸组的组内疲劳更大(可能是小的),而在冲刺 6-9 次时可能更小。咖啡因和牛磺酸补充剂对基线时的 HR 有较大影响(效应量=0.94),对冲刺 5 次和 10 次后 B[la]的增加有较小的影响(可能较小)。补充剂对 RPE 没有影响(不太清楚,微小)。以相当于商业能量饮料的剂量给予咖啡因和牛磺酸并没有提高重复冲刺自行车性能,并且似乎在选定的冲刺中引起更大的疲劳,特别是在试验结束时。这种不良的性能影响与心率的增加和糖酵解代谢产物的增加同时发生。