停經後婦女從事多元運動後停止運動與再訓練對肌肉表現之影響

Effects of multicomponent exercise, detraining, and retraining on muscle performance in postmenopausal women

目標：女性停經與老化的激素分泌量變化使肌肉力量與質量提早衰退。世界衛生組織和美國運動醫學會皆建議老年人從事多元運動。因此，本研究希望探討多元運動、停止運動與再訓練對停經後婦女肌肉表現之影響。方法：招募停經後婦女33位（年齡：67.2±5.3歲；身高：156.5±5.5 cm；體重：58.1±8.6 kg）。隨機區分實驗組與對照組，實驗組進行12週多元運動，隨後停止運動12週與再訓練8週；對照組維持常態生活。測量介入前（T1）、介入後（T2）、停止運動後（T3）與再訓練後（T4）等四個時間點的坐到站測試之力學特徵與骨骼肌肉質量指數（SMI）。力學參數包括對地面作用力峰值、到達峰值時間與坐姿到站姿時間等，可用以評估下肢肌肉力量、收縮速度及動態平衡能力等。使用二因子混合設計變異數分析力學特徵與SMI變化，α= .05。結果：實驗組的作用力峰值T2顯著高於T1（p< .001），T3顯著低於T2（p< .001），T4顯著高於T3與T1（p< .001; p< .001），並與對照組產生差異（p= .047）。實驗組的到達峰值時間T4顯著小於T1及T3（p= .003; p= .018），亦與對照組T4產生差異（p< .001）。SMI方面實驗組T2與T4顯著高於T1（p= .028; p= .006），對照組無改變。結論：多元運動能提高停經後婦女的肌肉質量與下肢肌肉力量。停止運動12週後，下肢肌肉力量顯著下降，但肌肉質量流失不明顯。再訓練8週能快速恢復肌肉質量與下肢肌肉力量。本研究成果可作為社區據點運動課程設計之參考。

Objectives: Menopause and aging-related hormonal changes lead to declines in muscle strength and mass in women. The World Health Organization and American College of Sports Medicine both recommend that older adults should engage in multicomponent exercise. This study investigated the effects of multicomponent exercise, detraining, and retraining on muscle performance in postmenopausal women. Methods: Thirty-three postmenopausal women (age: 67.2±5.3 years) were randomly assigned to an experimental or a control group. The experimental group underwent 12 weeks of multicomponent exercise followed by 12 weeks of detraining and 8 weeks of retraining; the control group maintained their normal lifestyle. Regarding mechanical characteristics, the sit-to-stand test was performed and the skeletal muscle mass index (SMI) measured at four time points: before training, after 12 weeks of training, after 12 weeks of detraining, and after 8 weeks of retraining. The mechanical parameters measured were the peak ground reaction force (GRF), time to reach peak force, and time from sitting to standing, which can be used to assess lower-limb muscle strength, contraction speed, and dynamic balance. Results: The peak GRF and SMI of the experimental group were significantly better than those of the control group after the training, decreased during the detraining, but then rapidly recovered during the retraining. Conclusions: Multicomponent exercise enhances muscle strength and mass in postmenopausal women. The results of this study can serve as a reference for the design of community-based exercise programs.