Age and sex affect human muscle fibre adaptations to heavy-resistance strength training
Age and sex affect human muscle fibre adaptations to heavy-resistance strength training
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DOI：
10.1113/expphysiol.2005.032771
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发表时间：
2006-03-01
影响因子：
2.7
通讯作者：
Rogers, MA
中科院分区：
文献类型：
--
作者：
Martel, GF;Roth, SM;Rogers, MA
这项研究评估了年龄和性别对肌纤维适应大阻力力量训练（ST）的影响。 22 名年轻男女（20-30 岁）和 18 名老年男女（65-75 岁）完成了 9 周的主腿大阻力膝关节伸展练习，每周 3 天（-1）；非主导腿作为受试者内部未经训练的控制。 ST 前后进行双侧股外侧肌活检，分析 I、IIa 和 IIx 型肌纤维横截面积 (CSA) 和纤维类型分布。 ST 之前和之后还评估了单次最大 (1-RM) 强度。 ST 导致年轻男性训练腿部的 I、IIa 和 IIx 型肌纤维、年轻女性的 I 和 IIa 型肌纤维、老年男性的 IIa 型肌纤维和老年女性的 IIx 型肌纤维的 CSA 增加（所有 P < 0.05）。纤维类型分布分析显示，仅在年轻女性中，ST 后 I 型纤维的百分比显着增加（P < 0.05），而 IIx 型纤维的百分比减少（P = 0.054）。对于任何组来说，未经训练的腿的肌纤维 CSA 或纤维类型分布都没有显着变化。所有组的 1-RM 均显着增加（27-39%；所有 P < 0.01）。总之，ST 导致所有组中 1-RM 和 II 型纤维 CSA 显着增加；然而，年龄和性别会影响特定肌纤维亚型对 ST 的反应。
This study assessed age and sex effects on muscle fibre adaptations to heavy-resistance strength training (ST). Twenty-two young men and women (20-30 years old) and 18 older men and women (65-75 years old) completed 9 weeks of heavy-resistance knee extension exercises with the dominant leg 3 days week(-1); the non-dominant leg served as a within-subject, untrained control. Bilateral vastus lateralis muscle biopsies were obtained before and after ST for analysis of type I, IIa and IIx muscle fibre cross-sectional area (CSA) and fibre type distribution. One-repetition maximum (1-RM) strength was also assessed before and after ST. ST resulted in increased CSA of type I, IIa and IIx muscle fibres in the trained leg of young men, type I and IIa fibres in young women, type IIa fibres in older men, and type IIx fibres in older women (all P < 0.05). Analysis of fibre type distribution revealed a significant increase in the percentage of type I fibres (P < 0.05) along with a decrease in type IIx fibres (P=0.054) after ST only in young women. There were no significant changes in muscle fibre CSA or fibre type distribution in the untrained leg for any group. All groups displayed significant increases in 1-RM (27-39%; all P < 0.01). In summary, ST led to significant increases in 1-RM and type II fibre CSA in all groups; however, age and sex influence specific muscle fibre subtype responses to ST.