Effects of caffeine on neuromuscular fatigue and performance during high-intensity cycling exercise in moderate hypoxia.
Effects of caffeine on neuromuscular fatigue and performance during high-intensity cycling exercise in moderate hypoxia.
复制标题
DOI：
10.1007/s00421-016-3496-6
复制
发表时间：
2017-01
影响因子：
3
通讯作者：
Marcora SM
中科院分区：
文献类型：
--
作者：
Smirmaul BP;de Moraes AC;Angius L;Marcora SM
研究咖啡因对中度缺氧高强度自行车运动期间表现、神经肌肉疲劳和努力感知的影响。七名成年男性参与者首先在急性常压缺氧（吸入氧分数= 0.15）的条件下在自行车测力计上进行增量运动测试，以确定峰值功率输出（PPO）。在接下来的两次访问中，他们采用双盲、随机、平衡交叉设计，在摄入咖啡因 (4 mg kg−1) 后在相同的低氧条件下进行了力竭时间测试 (78 ± 3% PPO)，并在摄入安慰剂后进行了一次力竭时间测试 (78 ± 3% PPO)。咖啡因可显着缩短 12% 的疲劳时间。摄入咖啡因后发现主观疲劳显着减少。与安慰剂相比，咖啡因条件下对努力的感知和股外侧肌的表面肌电信号幅度较低，心率较高。然而，咖啡因并不能减轻中度缺氧情况下高强度自行车运动引起的外周和中枢疲劳。在中度缺氧的高强度自行车运动中，咖啡因引起的力竭时间的改善似乎是通过努力感知的减少来介导的，尽管神经肌肉疲劳没有减少，但这种情况还是发生了。
To investigate the effects of caffeine on performance, neuromuscular fatigue and perception of effort during high-intensity cycling exercise in moderate hypoxia. Seven adult male participants firstly underwent an incremental exercise test on a cycle ergometer in conditions of acute normobaric hypoxia (fraction inspired oxygen = 0.15) to establish peak power output (PPO). In the following two visits, they performed a time to exhaustion test (78 ± 3% PPO) in the same hypoxic conditions after caffeine ingestion (4 mg kg−1) and one after placebo ingestion in a double-blind, randomized, counterbalanced cross-over design. Caffeine significantly improved time to exhaustion by 12%. A significant decrease in subjective fatigue was found after caffeine consumption. Perception of effort and surface electromyographic signal amplitude of the vastus lateralis were lower and heart rate was higher in the caffeine condition when compared to placebo. However, caffeine did not reduce the peripheral and central fatigue induced by high-intensity cycling exercise in moderate hypoxia. The caffeine-induced improvement in time to exhaustion during high-intensity cycling exercise in moderate hypoxia seems to be mediated by a reduction in perception of effort, which occurs despite no reduction in neuromuscular fatigue.