目的：探討人體進行離心運動引起肌肉損傷（exercise-induced muscle damage, EIMD）前，進行低強度跑步運動對跑步經濟性的影響。方法：以16名大學健康男性隨機分組至低強度跑步（long low-intensity running, LLR）或控制（control, CON）組。LLR組雙腿分別在從事最大等速離心收縮（maximal isokinetic eccentric contractions, MAX）前進行1小時水平坡度跑步。在跑步運動的前與後，進行身體肌肉表層溫度、核心溫度、超音波血流攝像測量。肌肉損傷及跑步經濟性指標安排在MAX前、後第0-5天、7及10天測驗。結果：LLR組進行1小時跑步後，溫度及血流均顯著提高（p＜.05）；不同兩組進行MAX後，其引起肌肉損傷程度及跑步經濟性變差情形，LLR組皆顯著低於CON組（p＜.05）。結論：在EIMD前，進行低強度跑步運動引起體溫及血流量顯著提高下，可減輕隨後EIMD症狀，進而減少跑步經濟性變差幅度。

Purpose: This study investigated the effects of the long low-intensity running exercise (LLR) on the indices of exercise-induced muscle damage (EIMD) and running economy of lower extremities before eccentric EIMD. Methods: Sixteen healthy young untrained men were randomly assigned into LLR or CON (control) group. The LLR group performed a bout of the maximal isokinetic eccentric contractions (MAX) of each knee extensors and flexors, by counterbalance, after performing a bout of 60-min low-intensity of level running. Body surface temperature (BST), core temperature (CT), and mean blood flow at femoral artery of ultrasound imaging (MBF) were measured immediately before and after low-intensity running for the LLR group. Muscle damage indicators [maximal voluntary isometric contraction strength (MVC), muscle soreness (SOR)], and running economy (RE) parameters [oxygen consumption (VO_2max), heart rate (HR), rating of perceived exertion (RPE), and blood lactate (LA)], were assessed before, 0-5, 7 and 10 days after MAX. Results: Significant (p＜.05) increases in BST, CT, and MBF immediately after 1-h running compared to baseline for the LLR group were observed. Changes in the all indicators of muscle damage and RE after MAX for both groups were significantly different compared to baseline. The changes in all measures after MAX for the LLR group were significantly smaller than the CON group. Conclusion: These results showed that protective effect of muscle damage and RE conferred by a bout of low-intensity running against a subsequent bout of MAX. Therefore, a bout of low-intensity running could be regarded as one of efficient preventive measures to reduce EIMD of both knee extensors and flexors, and RE performances.

最大等長肌力; 肌肉酸痛; 攝氧量; 血流量; 溫度

maximal voluntary isometric contraction strength; muscle soreness; oxygen consumption; blood flow; temperature