動態恢復強度對損傷肌肉之功能及跑步經濟性的影響

Effects of different active recovery intensities on muscle function and running economy after exercise-induced muscle damage

"目的：探討肌肉損傷後從事6天不同強度的動態恢復活動（50％、60％、70％V.O2max），對肌肉功能恢復及跑步經濟性的影響。方法：以40名自願參加本實驗之大學體育相關科系學生為受試對象。先接受V.O2max及跑步經濟性測驗後，再將受試者隨機分派E50組（n＝10）、E60組（n＝10）、E70組（n＝10）、CON組（n＝10）。之後讓受試者在跑步機上以70％V.O2max的強度進行一次30分鐘的下坡跑（-15％），來誘發股四頭肌產生肌肉損傷。在下坡跑後第1－6天期間，分別以不同的強度進行每天30分鐘的跑步運動。各組在下坡跑前、後第0－7天接受肌肉酸痛及最大自主等長收縮肌力（MVC）測量；各組在下坡跑前、後第1、3、5、7天抽血檢驗肌酸激酶（CK）及乳酸脫氫酶（LDH）活性；下坡跑後第2、5、7天接受跑步經濟性測驗。結果：下坡跑後第4－7天，CON組與E50組的MVC恢復情形顯著高於E70組。下坡跑後第7天的跑步經濟性測驗中，E50組顯著優於CON組與E70組。在CK、LDH、肌肉酸痛指數等指標上，不同四組在不同時間點上均無顯著差異。結論：1.採用完全休息或中強度的動態恢復（50％V.O2max），是最大肌力儘快恢復的較好選擇。越高的動態恢復強度，越會延緩MVC的恢復時程。2.過高的動態恢復強度（70％V.O2max）或不做動態恢復的處理方式，則對跑步經濟性有不利的影響。3.同時考量跑步經濟性及MVC恢復情形因素，則中強度的動態恢復（50％V.O2max）比不從事動態恢復和高強度動態恢復來得好。Purpose: To determine the effect of a 6-day different intensities active recovery (50% 、60% 、70% V.O2max) on muscle function and running economy after exercise-induced muscle damage. Methods: Forty P. E. students (32 males & 8 females) were placed into one of four groups-CON, E50, E60 and E70. A 30-min downhill running (-15%) at 70% V.O2max was used to cause muscle damage. A 30-min active recovery running exercise was performed everyday for the following 6 days. Maximal isometric voluntary contraction strength (MVC) and muscle soreness were measured before, immediately after and 1, 2, 3, 4, 5, 6, 7 days after downhill running. Creatine kinase (CK) and lactate dehydrogenase (LDH) activities were also tested before, immediately after and 1, 3, 5, 7 days after downhill running. Running economy was determined 2, 5, 7 days after downhill running. Results: On the days 4-7, both the CON's and E50's MVC were significantly higher than the E70 (p< .05). On the seventh day of the running economy test after downhill running, E50 was significantly different as compared to CON and E70 (p< .05). No significant differences among groups in CK activity, LDH activity and muscle soreness (p> .05) were observed. Conclusions: 1. Rest or moderate intensity active recovery (about 50% V.O2max) was better for MVC recovery. Higher intensity of active recovery would delay the normal recovery course of MVC. 2. Higher intensity of active recovery or rest was harmful to running economy. 3. When consider running economy and MVC together, moderate intensity of active recovery (about 50% V.O2max) was better than rest or high intensity active recovery."