下坡跑誘發肌肉損傷對隔天高脂肪餐後血脂濃度之影響

Abstract

研究背景：先前研究認為持續性長時間的有氧運動可以藉由運動中的能量消耗，降低隔天高脂肪餐後的血脂濃度，而阻力訓練所造成的全身性肌肉損傷可能會抵消運動降低餐後血脂濃度的效果，但目前仍不瞭解有氧運動導致的肌肉損傷對餐後血脂濃度的影響。目的：本研究目的為利用下坡跑形式探討有氧運動介入誘發肌肉損傷，探討有氧運動後的肌肉損傷對隔天餐後血脂濃度的影響。研究方法：招募9位健康成年男性採用隨機分配實驗設計，以60% VO2max強度進行30 min下坡跑 (downhill running, DR)、30 min平坡跑 (level running, LR) 及30 min休息 (control, CON) 共三次測試，於運動後攝取一標準晚餐後，禁食12 hr後進行高脂肪餐測試 (fat, 1.2g/kg; CHO, 1.1 g/kg; protein, 0.33 g/kg; kcal, 16.5 kcal/kg)，探討餐後後0.5, 1, 2, 3, 4, 5, 6 hr血脂濃度及呼吸交換率 (respiratory exchange ratio, RER) 的變化。結果：三次測試的高脂肪餐後各時間點血清三酸甘油酯濃度及濃度與時間曲線下面積無顯著差異，DR測試餐後血清游離脂肪酸濃度時間曲線下面積顯著高於CON測試 (p = 0.03) ，但甘油濃度在三個測試間無顯著差異；DR測試餐後HDL-C濃度於0, 0.5, 1 hr顯著高於CON測試 (p<.05) ；DR測試餐後6 hr血清肌酸激酶濃度顯著高於LR及CON測試 (p<.05)。結論：本研究發現下坡跑有氧運動產生的肌肉損傷誘發隔天肌肉損傷指標物質肌酸激酶濃度上升，此肌肉損傷對餐後血液三酸甘油酯代謝無顯著影響，但可能降低肌肉對餐後血液游離脂肪酸的代謝。Background: Muscle damage could alter the effect of endurance exercise on postprandial lipemia. Objective: The purpose of this study was to investigate the effects of downhill running on postprandial lipemia. Methodology: Nine healthy adult males performed three trials: downhill running at 60% VO2max for 30 minutes (DR), level running at 60% VO2max for 30 minutes (LR), and rest for 30 min (CON) in a randomized cross-over design. A standardized dinner was consumed after the running or rest. After a 12-hr fast, a high-fat meal (fat, 1.2g/kg; CHO, 1.1 g/kg; protein, 0.33 g/kg; kcal, 16.5 kcal/kg) was ingested. Blood samples and expired gas were collected at 0, 0.5, 1, 2, 3, 4, 5, 6 hr. Results: Postprandial triglyceride concentrations and the area under the curve were not significantly different among the three trials. Non-esterified fatty acids area under the cruve was significantly higher in DR than CON (p = 0.03). However, serum glycerol concentrations were similar among the three trials. HDL-C concentrations were significantly higher in DR than CON at 0, 0.5, 1 hr after the high fat meal. (p<.05). Creatine kinase concentrations were significantly higher in DR than LR and CON at each time point (p <.05). Conclusion: This study suggested that muscle damage induced by downhill running had no effect on postprandial triglyceride concentration. However, muscle damage could reduce the postprandial metabolism of non-esterified fatty acids.