Sport Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Vitoria de Santo Antao, Pernambuco, Brazil.
Human Performance Research Group, Academic Department of Physical Education, Federal University of Technology - Parana, Curitiba, Parana, Brazil.
PLoS One. 2019 Nov 7;14(11):e0224794. doi: 10.1371/journal.pone.0224794. eCollection 2019.
This study investigated the effect of caffeine on neuromuscular function, power and sprint performance during the days following an eccentric-based exercise. Using a randomly counterbalanced, crossover and double-blinded design, eleven male jumpers and sprinters (age: 18.7 ± 2.7 years) performed a half-squat exercise (4 x 12 repetitions at 70% of 1 RM), with eccentric action emphasized by using a flexible strip attached to their knees (Tirante Musculador®). They ingested either a capsule of placebo or caffeine (5 mg.kg-1 body mass) 24, 48 and 72 h after. Neuromuscular function and muscle power (vertical countermovement-jump test) were assessed before and after the half-squat exercise and 50 min after the placebo or caffeine ingestion at each time-point post-exercise. Sprint performance was measured at pre-test and 75 min after the placebo or caffeine ingestion at each time-point post-exercise. Maximal voluntary contraction (overall fatigue) and twitch torque (peripheral fatigue) reduced after the half-squat exercise (-11 and -28%, respectively, P < 0.05) but returned to baseline 24 h post-exercise (P > 0.05) and were not affected by caffeine ingestion (P > 0.05). The voluntary activation (central fatigue) and sprint performance were not altered throughout the experiment and were not different between caffeine and placebo. However, caffeine increased height and power during the vertical countermovement-jump test at 48 and 72 h post half-squat exercise, when compared to the placebo (P < 0.05). In conclusion, caffeine improves muscle power 48 and 72 h after an eccentric-based exercise, but it has no effect on neuromuscular function and sprint performance.
本研究旨在探讨咖啡因对离心运动后几天内神经肌肉功能、功率和短跑表现的影响。采用随机交叉双盲设计，11 名男性跳跃和短跑运动员（年龄：18.7 ± 2.7 岁）进行半蹲运动（4 x 12 次，重复 70%的 1RM，使用附在膝盖上的弹性带（Tirante Musculador®）强调离心动作。他们在离心运动后 24、48 和 72 小时分别摄入安慰剂或咖啡因（5mg.kg-1 体重）胶囊。在半蹲运动前后以及安慰剂或咖啡因摄入后 50 分钟，评估神经肌肉功能和肌肉力量（垂直反跳测试）。在每个时间点，在半蹲运动后进行短跑测试，并在每个时间点的安慰剂或咖啡因摄入后 75 分钟进行测量。最大自主收缩（整体疲劳）和抽搐扭矩（外周疲劳）在半蹲运动后降低（分别为-11%和-28%，P < 0.05），但在运动后 24 小时恢复基线（P > 0.05），并且不受咖啡因摄入的影响（P > 0.05）。自愿激活（中枢疲劳）和短跑表现在整个实验中没有改变，在咖啡因和安慰剂之间也没有差异。然而，与安慰剂相比，咖啡因在半蹲运动后 48 和 72 小时增加了垂直反跳测试中的高度和功率（P < 0.05）。总之，咖啡因可改善离心运动后 48 和 72 小时的肌肉力量，但对神经肌肉功能和短跑表现没有影响。
