中高齡者的阻力訓練：動作速度的影響

Resistance training for the middle-aged and older adults: Effects of movement velocity

骨骼肌質量、肌力與爆發力隨年齡增加而下降，其中骨骼肌爆發力隨老化下降的速度又快於肌肉質量與肌力下降的速度。骨骼肌收縮力量與速度在功能性身體表現（如坐站能力與爬梯能力）及跌倒預防上扮演重要的角色，也因此中高齡者的阻力訓練一再被強調。目前實務上，多數教練為避免中高齡者於運動過程中受傷，教導阻力運動時多建議高齡者慢慢地完成動作。然而，有鑑於骨骼肌的爆發力與功能性身體表現呈正相關，本文回顧並整理中高齡者較常忽略的高速（以最快速度完成向心收縮動作）阻力運動與其訓練成效，藉此提供中高齡者進行有效且安全阻力運動之依據。彙整研究的結果發現，在訓練阻力相同的狀況下，最大肌力的增加幅度與動作速度無關。在爆發力的訓練成效上，如果訓練阻力相同，則高速阻力訓練較低速（以2－3秒完成向心收縮動作）阻力訓練，能有效增加爆發力。漸進式增加阻力為運動安全的最高原則，彙整研究結果後建議對於缺乏活動、身體功能受限、或無法承受高阻力訓練的長者，可藉由每週2－3次，為期10週以上的高速低至中高阻力（40% 1RM [one-repetition maximum]），每個動作重複8－14下、2－3回合；或第1回合以45％1RM，第2回合以60％1RM，第3回合以75％1RM進行，每回合每個動作皆重複8下；或依據可以產生的最大功率為原則，不同動作以50～80％1RM進行，每個動作重複10－12下、3回合）訓練增加其對阻力運動的接受度並得到增加肌力、爆發力與身體功能的效果。對於健康、身體功能佳、已有阻力運動習慣的長者，可帶領中高強度（60～70％1RM、每個動作重複6－10下、2－3回合）、以最快速度進行收縮的阻力訓練，每週2－3次，執行10週以上，以達增進肌力、爆發力與功能性身體表現的最佳效果。阻力訓練相關的不良事件，以關節疼痛與肌肉痠痛為主，建議應循序漸進，避免運動訓練初期即採用高速高阻力的訓練。

Muscle strength and muscle power decline with aging, and the decline of muscle power is even faster than the decline of muscle strength. Skeletal muscle contractile force and velocity play an important role in functional performance (such as sit-to-stand and stair-climbing) and the fall prevention. Resistance exercise is the best exercise mode to increase muscle strength and prevent age-related muscle dysfunction. In current practice, most coaches advise middle-aged and elderly people to complete their movements slowly during resistance exercise to prevent exercise-related injury. However, in view of the positive correlation between muscle power and functional performance, this article reviewed the evidence about the effectiveness of high-velocity resistance training on muscle function and functional performance of middle-aged and elderly people. In addition, training-related adverse events was also examined. The research evidence showed that, with the same resistance, the increase of maximum muscle strength is independent of the contractile velocity, and high-velocity resistance training is more effective in improving muscle power than low-velocity resistance training. As the gradual increase in resistance is the highest principle of exercise safety, after compiling the research results, it is recommended that older individuals who are sedentary, have some limitation on physical functions, or unable to withstand high training resistance, could perform high-velocity, low- to moderate-intensity resistance training (40% one-repetition maximum (1RM), 8-14 repetitions, 2-3 sets; or 8 repetitions at 45% 1RM for the set 1, 8 repetitions at 60% 1RM for the set 2, and 8 repetitions at 75% 1RM for the set 3; or 50~80% 1RM based on optimal loads that maximized power outputs of the training machines, 10-12 repetitions, 3 sets), 2-3 times per week for at least 10 weeks, to improve their muscle strength, muscle power and functional performance. For elders who are healthy, have good body functions, and are resistance training exerciser, they can be suggested to perform resistance training with high-intensity and fast contraction (60~70% 1RM or the intensity of a little hard to hard feeling, 6-10 repetitions, 2-3 sets), 2-3 times per week for at least 10 weeks, to maximize the training effects on muscle strength, muscle power and functional performance. The adverse events related to resistance training are mainly joint pain and muscle soreness. It is recommended to proceed step by step during training. Those who have no resistance training experience are not recommended to perform high-velocity and high-resistance training at the beginning of the exercise training.