Kwak Minyoung, Succi Pasquale J, Benitez Brian, Mitchinson Clara J, Bergstrom Haley C
Department of Kinesiology and Health Promotion, The University of Kentucky, Lexington, KY, USA.
Appl Physiol Nutr Metab. 2025 Jan 1;50:1-12. doi: 10.1139/apnm-2024-0181. Epub 2024 Sep 19.
Fatigability varies depending on sex and contraction intensity during sustained exercise. This study examined the responses of time to task failure (TTF), performance fatigability (PF), and muscle oxygenation (SmO) in males and females during isometric handgrip holds to failure (HTF) at 30% and 60% maximum voluntary isometric contraction (MVIC). Males ( = 12) and females ( = 12) performed a pre-MVIC, handgrip HTF at randomly ordered percentages of MVIC (either 30% or 60%), followed by a post-MVIC on the dominant arm. During the HTF testing, the TTF and SmO responses were recorded, and PF was determined from the pre- to post-MVICs. TTF for 30% MVIC HTF was greater than 60% MVIC HTF ( < 0.001), but was not different between males and females ( = 0.117). PF exhibited an inverse relationship with intensity for each sex, while males demonstrated greater PF than females for both 30% and 60% MVIC HTF. For the 60% MVIC HTF, males demonstrated greater desaturation than females (CI = [-28.1, -2.6%], = 0.021, = 0.621), but not for the 30% MVIC HTF (CI = [-12.2, 7.9%], = 0.315, = 0.621). Sex differences in PF and SmO may be attributed to the differences in muscle mass, absolute strength, contractile properties, and muscle metabolism between males and females. However, these proposed differences between males and females may not fully inform exercise performance (e.g., TTF). Sex-specific fatigue responses may be affected by complex physio-psychological mechanisms, and therefore, additional investigations under diverse exercise conditions are required to better prescribe exercise for both males and females.
在持续运动过程中，疲劳程度会因性别和收缩强度的不同而有所变化。本研究调查了男性和女性在以最大自主等长收缩（MVIC）的30%和60%进行等长握力直至力竭（HTF）过程中，任务失败时间（TTF）、运动疲劳性（PF）和肌肉氧合（SmO）的反应。12名男性和12名女性在优势手臂上进行了预MVIC测试，然后以随机顺序进行MVIC的30%或60%的握力HTF测试，最后进行后MVIC测试。在HTF测试期间，记录TTF和SmO反应，并根据预MVIC和后MVIC确定PF。30%MVIC HTF的TTF大于60%MVIC HTF（P<0.001），但男性和女性之间无差异（P=0.117）。每种性别的PF都与强度呈反比关系，在30%和60%MVIC HTF时，男性的PF均高于女性。对于60%MVIC HTF，男性的去饱和程度高于女性（CI = [-28.1, -2.6%]，P = 0.021，η² = 0.621），但对于30%MVIC HTF则不然（CI = [-12.2, 7.9%]，P = 0.315，η² = 0.621）。PF和SmO的性别差异可能归因于男性和女性在肌肉质量、绝对力量、收缩特性和肌肉代谢方面的差异。然而，这些提出的男性和女性之间的差异可能无法完全说明运动表现（如TTF）。性别特异性疲劳反应可能受复杂的生理心理机制影响，因此，需要在不同运动条件下进行更多研究，以便更好地为男性和女性制定运动方案。
