缺血預適應結合低強度阻力訓練改善肌肉適能之探討

The Improvement of Muscular Fitness through Ischemia Preconditioning Combined with Light Resistance Training

缺血預適應（ischemia preconditioning,IPC）結合低強度阻力訓練（light resistance training,LRT）引起運動後組織的低氧、pH值下降可促進生長激素分泌與mammalian target of rapamycin（mTOR）路徑活化，進而增加肌肉的合成，且經由其橫向遷移的效果，不僅可改善加壓部位的肌肉適能，更能提升未加壓肌群的肌力與肌橫斷面積（如胸大肌），同時避免高強度阻力訓練所引起的受傷風險，適合不同肌肉適能水準之對象，如老年人、一般人、運動員與心血管疾病病患。透過結合式訓練可提升一般人相對肌力，並可應用於運動員傷後復健期，是一種安全且快速恢復肌肉適能的策略。研究結果顯示20～50%1RM+LRT皆能有效提升肌肉適能，但為了取代高強度阻力訓練，研究建議下肢訓練強度應≧30%1RM。在加壓方面，147～160mmHg可達到上臂運動肌電最佳的活化程度，但為了符合每位受試者的需求，仍須發展出最佳相對加壓方式，如個人收縮血壓的倍數或運動自覺量表值。最後，因訓練強度與加壓程度皆會影響訓練結果，如何在兩者之間找到一個最佳的訓練處方組合以應用於不同的對象與肌群，值得未來更進一步的研究。

Combined ischemia preconditioning (IPC) with light resistance training (LRT) induces muscular hypoxia and decreases the pH. It augments muscular synthesis by increasing growth hormone secretion and mammalian target of rapamycin (mTOR) pathway activation post-exercise and so improves muscular fitness. The cross-transfer effects of IPC+LRT not only increase strength and cross-sectional area in occluded muscle and the non-occluded muscles (such as pectorals), but also decrease the injury risks suffered by different groups (healthy, athlete, elderly and patient with cardiovascular disease). The cooperative effects of such training enhance the relative strength of healthy people, and can be applied to injured athlete as a strategy to regain muscular fitness quickly. Studies revealed that muscular fitness can be improved with 20~50% 1RM+IPC. To replace the high intensity resistance training, the recommended intensity for lower limbs is ≧30% 1RM. 147~160 mmHg can induce the optimal exercise electromyogram activation for the upper arms. However, in order to meet the need of every subjects, it should develop the optimal relative occlude pressure for different people in the future such as a multiple of personal systolic blood pressure or rating of perceived exertion. Both training intensity and occlude pressure would influence the training result. The indication for further studies to establish the optimal prescription for different subjects and muscles is obvious.