Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.
Exp Physiol. 2024 Oct;109(10):1650-1662. doi: 10.1113/EP091937. Epub 2024 Aug 6.
The gradual deterioration of physiological systems with ageing makes it difficult to maintain skeletal muscle mass (sarcopenia), at least partly due to the presence of 'anabolic resistance', resulting in muscle loss. Sarcopenia can be transiently but markedly accelerated through periods of muscle disuse-induced (i.e., unloading) atrophy due to reduced physical activity, sickness, immobilisation or hospitalisation. Periods of disuse are detrimental to older adults' overall quality of life and substantially increase their risk of falls, physical and social dependence, and early mortality. Disuse events induce skeletal muscle atrophy through various mechanisms, including anabolic resistance, inflammation, disturbed proteostasis and mitochondrial dysfunction, all of which tip the scales in favour of a negative net protein balance and subsequent muscle loss. Concerningly, recovery from disuse atrophy is more difficult for older adults than their younger counterparts. Resistance training (RT) is a potent anabolic stimulus that can robustly stimulate muscle protein synthesis and mitigate muscle losses in older adults when implemented before, during and following unloading. RT may take the form of traditional weightlifting-focused RT, bodyweight training and lower- and higher-load RT. When combined with sufficient dietary protein, RT can accelerate older adults' recovery from a disuse event, mitigate frailty and improve mobility; however, few older adults regularly participate in RT. A feasible and practical approach to improving the accessibility and acceptability of RT is through the use of resistance bands. Moving forward, RT must be prescribed to older adults to mitigate the negative consequences of disuse atrophy.
随着年龄的增长，生理系统逐渐恶化，使得维持骨骼肌质量（肌少症）变得困难，至少部分原因是存在“合成代谢抵抗”，导致肌肉损失。由于体力活动减少、患病、固定或住院等原因，肌肉失用（即去负荷）导致的萎缩会暂时但明显加速肌少症的发展。失用期会对老年人的整体生活质量产生不利影响，并大大增加他们跌倒、身体和社会依赖以及早逝的风险。失用事件通过多种机制引起骨骼肌萎缩，包括合成代谢抵抗、炎症、蛋白质稳态紊乱和线粒体功能障碍，所有这些都导致净蛋白平衡向负面倾斜，随后发生肌肉损失。令人担忧的是，老年人从失用性萎缩中恢复比年轻人更困难。阻力训练（RT）是一种有效的合成代谢刺激，可以在老年人去负荷前、去负荷期间和去负荷后强有力地刺激肌肉蛋白合成，减轻肌肉损失。RT 可以采取传统以举重为重点的 RT、体重训练以及低负荷和高负荷 RT 的形式。当与足够的膳食蛋白质结合时，RT 可以加速老年人从失用事件中恢复，减轻虚弱并提高活动能力；然而，很少有老年人经常进行 RT。一种可行且实用的方法是使用阻力带，以提高 RT 的可及性和可接受性。展望未来，必须为老年人规定 RT，以减轻失用性萎缩的负面影响。
