Institute of Food, Nutrition and Human Health, Massey University, Palmerston, New Zealand.
J Strength Cond Res. 2010 Feb;24(2):494-501. doi: 10.1519/JSC.0b013e3181c06af3.
Isometric contractions, such as occurring during rock climbing, occlude blood flow to the active musculature. The ability to maximize forearm blood flow between such contractions is a likely determinant of intermittent handgrip performance. This study aimed to test the hypothesis that intermittent isometric handgrip performance is improved by 2 common active recovery strategies suggested to increase muscle blood flow. On 6 separate occasions, 9 trained indoor rock climbers and 9 untrained participants undertook a fatiguing, intermittent, isometric handgrip exercise bout consisting of sets of 6 contractions (approximately 33% of maximal voluntary contraction [MVC] force), each 3-second long separated by a 1-second rest. Between sets, participants were allowed 9-second recovery performing passive rest, "shaking out" (vigorously shaking the hand), or grasping a handgrip vibration machine, each with or without forearm occlusion. Performance was assessed by pre- and post-exercise MVC trials and a 20-contraction post-exercise handgrip time trial (TT20). Trained climbers exhibited significantly greater handgrip MVC force and intermittent exercise capacity than untrained (p < 0.01). There was no effect of recovery strategy on any measure (p > 0.05). Trained climbers were more affected by occlusion than untrained in MVC (p < 0.05) and TT20 (p < 0.01). Shaking out and low-frequency vibration are unlikely to affect rock climbing performance. It is recommended that rock climbers and their coaches focus on optimizing body position rather than compromising body position to allow for shaking out.
等长收缩,如攀岩时发生的收缩,会阻断活跃肌肉的血液流动。在这种收缩之间最大限度地增加前臂血液流动的能力可能是间歇性握力表现的决定因素。本研究旨在检验以下假设:通过 2 种常见的主动恢复策略,间歇性等长握力表现得到改善,这两种策略被认为可以增加肌肉血液流动。在 6 个不同的场合,9 名训练有素的室内攀岩者和 9 名未经训练的参与者进行了一项疲劳的、间歇性的、等长握力运动,包括 6 组收缩(约为最大自主收缩[MVC]力的 33%),每组收缩持续 3 秒,间隔 1 秒休息。每组之间,参与者有 9 秒的恢复时间,可以进行被动休息、“抖动”(用力抖动手部)或抓握握力振动器,每种方法都可以或不可以进行前臂闭塞。通过运动前和运动后的 MVC 试验以及运动后的 20 次握力时间试验(TT20)来评估表现。训练有素的攀岩者的握力 MVC 力量和间歇性运动能力明显大于未经训练的(p < 0.01)。恢复策略对任何指标都没有影响(p > 0.05)。与未经训练的人相比,受过训练的攀岩者在 MVC(p < 0.05)和 TT20(p < 0.01)中受到的闭塞影响更大。抖动和低频振动不太可能影响攀岩表现。建议攀岩者及其教练专注于优化身体姿势,而不是为了抖动而妥协身体姿势。