Phillips Kevin, Noh Byungjoo, Gage Matthew, Yoon Tejin
a Department of Kinesiology and Integrative Physiology , Michigan Technological University , Houghton , MI , USA.
Eur J Sport Sci. 2017 Aug;17(7):885-893. doi: 10.1080/17461391.2017.1328707. Epub 2017 May 22.
Different ambient temperatures are known to affect muscular performance based on the type of contraction. The effect of cold (10°C) and thermoneutral (TN) (24°C) ambient temperatures on finger flexor performance was examined in 12 rock climbers. After 30 min of seated rest in the designated temperature condition, participants completed maximal voluntary contractions (MVC) on a climbing-specific finger flexor assessment device equipped with a crimp grip hold. Participants then completed an intermittent fatiguing task until failure. The fatiguing task consisted of 10-s contractions at 40% MVC followed by a 3-s of rest. MVC recovery was assessed immediately, 5, 10, and 15 min post-task failure. Estimated muscle temperature and subjective thermal ratings were significantly lower throughout testing in the cold condition (P < .001). Finger flexor MVC strength was similar between conditions at baseline and throughout recovery. Time to task failure was significantly longer (364 ± 135 vs. 251 ± 97 s, P = .003) and force time integral was greater (53,715 ± 19,988 vs. 40,243 ± 15,360 Ns, P = .001) during the cold condition. No significant differences were found between conditions for force variability or electromyography (EMG) at the start and end of the fatiguing task. However, the rate of increase in EMG for the TN condition was significantly faster (P = .03). These results suggest important implications for researchers when examining climbing performance, especially in outdoor settings where temperatures may vary from day to day. Inconsistencies in testing temperatures might significantly affect muscular endurance.
已知不同的环境温度会根据收缩类型影响肌肉表现。在12名攀岩者中研究了寒冷（10°C）和热中性（TN）（24°C）环境温度对手指屈肌表现的影响。在指定温度条件下静坐休息30分钟后，参与者在配备有抓握把手的特定攀岩手指屈肌评估装置上完成最大自主收缩（MVC）。然后参与者完成一项间歇性疲劳任务直至疲劳衰竭。疲劳任务包括以40%MVC进行10秒收缩，随后休息3秒。在任务失败后立即、5分钟、10分钟和15分钟评估MVC恢复情况。在寒冷条件下，整个测试过程中估计的肌肉温度和主观热感觉评分显著更低（P < 0.001）。在基线和整个恢复过程中，各条件下手指屈肌MVC力量相似。在寒冷条件下，任务失败时间显著更长（364±135 vs. 251±97秒，P = 0.003），且力-时间积分更大（53,715±19,988 vs. 40,243±15,360 Ns，P = 0.001）。在疲劳任务开始和结束时，各条件下的力变异性或肌电图（EMG）无显著差异。然而，TN条件下EMG的增加速率显著更快（P = 0.03）。这些结果表明，对于研究攀岩表现的研究人员具有重要意义，尤其是在户外环境中，温度可能每天都有所不同。测试温度的不一致可能会显著影响肌肉耐力。
