目的:探討四週beta-丙胺酸增補對下坡跑運動後肌肉損傷的影響。方法:16名大專男性學生進行分組:beta-丙胺酸組或安慰劑組。以雙盲實驗設計進行增補,每日攝取三次(共4.8克)並持續增補四週後,進行30分鐘強度70% VO^2max的下坡跑運動,並於運動前、運動後24-72小時進行肌肉損傷指標與氧化傷害指標的檢測。結果:beta-丙胺酸組只有肌酸激酶於運動後72小時顯著低於安慰劑組、以及關節活動角度於運動後48與72小時,顯著高於安慰劑組。此外,在運動前或運動後beta-丙胺酸組的丙二醛都顯著低於安慰劑組。結論:四週的beta-丙胺酸增補可能具有減緩下坡跑運動後肌肉損傷的效益,特別是降低肌酸激酶與促進關節活動角度的恢復。另外,beta-丙胺酸的增補也可能具有減緩氧化傷害的效益。
Purpose: This study aimed to investigate the effects of four-week beta-alanine supplementation on muscle damage induced by downhill running. Methods: 16 male college students were assigned into beta-alanine group and placebo group. This study was performed in a double-blind experimental design. Participants received beta-alanine supplements (4.8 g‧d^(-1)) or placebos three times a day for 4 weeks. After four-week supplementation, all participants performed downhill running on treadmill lasted for 30 mins at a speed corresponding to intensity of 70% VO_2max. Muscle damage and oxidative damage parameters were measured before, and 24-72 hours after running. Results: Only creatine kinase (CK) in beta-alanine group was significantly lower at 72 hours post-exercise and range of motion (ROM) in beta-alanine group was significantly higher at 48 and 72 hours post-exercise when compared to placebo group. Moreover, malondialdehyde (MDA) was significantly lower in beta-alanine group than in placebo group, regardless of times. Conclusion: Four weeks of beta-alanine supplementation may have benefits in reducing the amount of muscle damage induced by downhill running, especially in CK and ROM. In addition, beta-alanine supplementation may also have benefits in reducing the oxidative damage induced by downhill running.