運動訓練與營養補充對失用性肌萎縮預防與治療效益之探討

The Current Understanding for the Potential Preventive and Therapeutic Effects of Exercise Training and Nutritional Supplementation on Disuse Muscle Atrophy

運動傷害與術後肢體固定會導致失用性肌萎縮，且對運動能力恢復產生負面影響，並間接增加訓練成本。本文中，我們探討失用性肌萎縮的分子生理調控機制與運動及營養介入策略。研究發現，肢體固定會導致肌細胞蛋白合成能力下降，同時活化蛋白酶系統，導致細胞凋亡與肌萎縮；但適當補充蛋白質或胺基酸等營養物質，對減緩失用性肌萎縮可能有正面效益。同時，移除肢體固定恢復活動後，必須進行運動訓練，才可使萎縮肌肉質量快速恢復。因此，失用性肌萎縮發生後，若整合運動訓練與營養補充，應可提高整體合成能力（例如：mTOR訊息系統），甚至改善失用過程引起的合成性代謝阻抗現象，但目前相關應用研究仍然不多見，故該主題將會是運動科學領域中有趣且具有實用價值的研究問題。

Sport injury and post-surgery immobilization lead to disuse muscle atrophy. Disuse atrophy not only has negative impacts on the recovery of exercise performance but also increase training cost. In this review article, we discussed the current understanding about physiological and molecular mechanisms for disuse muscle atrophy and possible intervention strategies using exercise training and nutritional supplementation. Recent evidence reveals that joint immobilization attenuates cellular protein synthetic capacity and activates proteolytic enzyme systems, thereby leading to apoptosis and rapid muscle wasting. However, provision of protein or amino acids may have positive effects on preventing disuse muscle atrophy. Moreover, exercise training is essential to regain muscle mass during remobilization period. Taken together, the combination of both exercise training and nutritional supplementation is possibly to enhance systemic anabolic capacity (e.g. mTOR pathway) and to reverse the anabolic resistance due to disuse. However, there are only few studies focusing on this topic, and it could be a substantially significant and interesting research question in exercise and sports science.