Walker Simon, Häkkinen Keijo
Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä, Jyväskylä, Finland.
J Strength Cond Res. 2014 Nov;28(11):3041-8. doi: 10.1519/JSC.0000000000000381.
This study investigated whether differences in neuromuscular performance and muscle hypertrophy occur between young and older men. Twenty-three young (29 ± 9 years) and 26 older men (64 ± 8 years) completed 10 weeks of high-volume, medium load "hypertrophic" resistance training with low frequency (twice per week) with 10 young (34 ± 11 years) and 11 older men (65 ± 3 years) acting as nontraining control subjects. Training consisted of 2-5 sets of 8-14 repetitions (1- to 2-minute rest). Lower-limb dynamic (leg press) and isometric maximum leg extension force, as well as lower-limb lean mass and vastus lateralis cross-sectional area were assessed before and after the training period. Training led to significant increases in 1 repetition maximum (1RM) leg press performance in both training groups (young: 13 ± 7%, p < 0.001; older: 14 ± 9%, p < 0.001). Performance improvements were accompanied by increased muscle activation, assessed by voluntary activation level (29 ± 51%, p ≤ 0.05) and electromyography amplitude (35 ± 51%, p < 0.01) in older men only. Conversely, only young men showed significantly increased lower-limb lean mass (2.4 ± 2.5%, p < 0.01). Furthermore, increases in 1RM performance and lower-limb lean mass were significantly related in young men only (r = 0.524, p = 0.01, n = 23). In conclusion, although high-volume, medium load "hypertrophic" resistance training may induce similar improvements in strength between young and older men, it appears that different mechanisms underpin these improvements.
本研究调查了年轻男性和老年男性在神经肌肉性能和肌肉肥大方面是否存在差异。23名年轻男性（29±9岁）和26名老年男性（64±8岁）完成了为期10周的大运动量、中等负荷的“肥大性”抗阻训练，训练频率较低（每周两次），另有10名年轻男性（34±11岁）和11名老年男性（65±3岁）作为非训练对照对象。训练包括2 - 5组，每组8 - 14次重复（休息1 - 2分钟）。在训练期前后评估下肢动态（腿举）和等长最大伸腿力量，以及下肢去脂体重和股外侧肌横截面积。训练使两个训练组的1次最大重复量（1RM）腿举表现都有显著提高（年轻组：13±7%，p<0.001；老年组：14±9%，p<0.001）。仅在老年男性中，表现的改善伴随着肌肉激活增加，通过自主激活水平（29±51%，p≤0.05）和肌电图幅度（35±51%，p<0.01）评估。相反，只有年轻男性的下肢去脂体重显著增加（2.4±2.5%，p<0.01）。此外，仅在年轻男性中，1RM表现的增加与下肢去脂体重的增加显著相关（r = 0.524，p = 0.01，n = 23）。总之，尽管大运动量、中等负荷的“肥大性”抗阻训练可能使年轻男性和老年男性在力量方面有相似程度的提高，但这些提高背后的机制似乎有所不同。
