支人类缓慢组件的机制
Enrico Tam1, Mauro Nardon2, Matteo Bertucco2
1Section of Movement Sciences, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Via Casorati 43, 37131, Verona, Italy. enrico.tam@univr.it.
European journal of applied physiology
|September 29, 2023
概括
在乳酸值 (LT) 以上的运动会增加氧气吸收 () 由于纤维的招募和减少收缩经济. 这项研究量化了在同度收缩期间的这些效应,揭示了收缩经济在很大程度上有助于增加.
科学领域:
- 运动生理学 运动生理学
- 肌肉生理学 肌肉生理学
- 生物能源学 生物能源学
背景情况:
- 在超过乳酸值 (LT) 的运动期间,氧气吸收的缓慢成分主要归因于II型肌肉纤维的招募.
- 然而,也有人提出肌肉收缩经济逐渐下降的潜在贡献.
研究的目的:
- 为了研究肌肉纤维招募和改变收缩经济的相对贡献,以缓慢组件的氧气吸收 () 在同位体运动期间.
- 通过操纵扭矩或电肌图学 (EMG) 活动来区分机制.
主要方法:
- 11名健康的志愿者在最大自愿收缩 (MVC) 的65%时进行了7分钟的同度腿延伸器收缩.
- 测试了两个条件:反控制的扭矩 (FB-Torque) 和反控制的EMG (FB-EMG),以保持持续的肌肉激活.
- 测量了净氧气吸收 () 和巨大的横向根平均平方 (RMS) EMG.
主要成果:
- 在FB-Torque条件下,氧气吸收 () 随着时间的推移而增加,但在FB-EMG条件下保持稳定.
- 扭矩比率仅在FB-Torque期间显著增加.
- 在这两种条件下,RMS最初增加,然后稳定,这表明尽管FB-Torque上升,但动力单元池保持不变.
结论:
- 收缩经济的逐渐衰退有助于在同位体运动期间氧气吸收 () 的缓慢组成部分.
- 在恒定扭矩条件下观察到的总增加中,这种内在机制约占18%.
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