探討不同進食狀態在不同運動強度對能量受質利用的影響

Abstract

本研究主要目的在探討不同進食狀態在不同運動強度對能量代謝的影響。12位健康男性利用平衡次序法， 隨機接受6小時空腹的未進食狀態(fast.Ft) 與進食後(500卡含糖55%、蛋白質15%、脂肪35% 的標準代餐)1小時的進食狀態(fed，Fd)後，在跑步機上連續以低(45% VO2max)、中(65% V02max)、高(85% V02max) 強度各進行20分鐘運動(85% VO2max 如無法運動20分鐘則以受試者衰竭時停止運動)。在運動前與每階段運動中共進行4次，每次5mL 的抽血取樣及運動中之氣體資料探集。分析血液中血糖(blood glucose, BG)、血乳酸(blood lactate，BL) 與運動中呼吸交換率(rispiractory exchange ratio,RER) 。結果顯示，Ft狀態於低與中運動強度下呼吸交換率顯著低於Fd狀態(p <.05) .而高強度下未進食與進食狀態無差異; Fd狀 態於高強度運動時血糖值顯著低於Ft狀態(p<.05) . 而在低與中運動強度則無差異; 無論在任一強度下未進食與進食狀態之血乳酸濃度均無差異。在未進食狀態下從事低與中強度運動會比進 食狀態下消耗更多的脂肪， 而高強度則沒有顯示此現象。進食狀態下進行高強度運動時， 血糖濃度會顯著的低於未進食狀態，其原因或許與飲食前所引起的高膜島素反應與高強度運動所引起的 葡萄糖運載體的促進刺激加成效果使然。

The purpose of this study was to investigate the effect of feeding state on metabolic substrate utilization during different exercise intensities. Twelve healthy male subjects performed treadmill exercise in a random and counter-balanced order for 60 mm including three sessions (20 min each ) of 45%, 65% and 85% VO(subscript 2max) sequential exercise after either 6h fasting (fasted, Ft) or 1h after a standard meal (500 Kcal, CHO: 55% Protein: 15% Fat: 35%) fed. Respiratory exchange ratios (RER), blood glucose (BG) and blood lactate (BL) concentrations were measured throughout each trial. RER was significantly lower in Ft state during 45% and 65% but not 85% VO(subscript 2max) exercise. Neither BL nor BG was found different between Ft and Fd state during any exercise intensity except that BG was lower in Fd state during 85% VO(subscript 2max). These data suggest that short-term fasting promotes fatty acid utilization particularly during low-and moderate-aerobic exercise but not high-intensity exercise, which relies more on carbohydrates. The lower BG may have resulted from a synergistic effect of post-meal hyperinsulinemia and high-intensity exercise causing the glucose transporters promotion ultimately resulting in a greater demand for carbohydrate.