Greer Beau Kjerulf, Woodard John L, White Jim P, Arguello Eric M, Haymes Emily M
Dept. of Physical Therapy and Human Movement Sciences, Sacred Heart University, Fairfield, CT 06825, USA.
Int J Sport Nutr Exerc Metab. 2007 Dec;17(6):595-607. doi: 10.1123/ijsnem.17.6.595.
The purpose of this study was to determine whether branched-chain amino acid (BCAA) supplementation attenuates indirect indicators of muscle damage during endurance exercise as compared with an isocaloric, carbohydrate (CHO) beverage or a noncaloric placebo (PLAC) beverage. Nine untrained men performed three 90 min cycling bouts at 55% VO 2peak. Subjects, blinded to beverage selection, ingested a total of 200 kcal of energy via the CHO or BCAA beverage before and at 60 min of exercise, or they drank the PLAC beverage. Creatine kinase (CK), lactate dehydrogenase (LDH), isokinetic leg-extension and -flexion torque, and muscle soreness were assessed before and immediately, 4 h, 24 h, and 48 h postexercise. The trials were separated by 8 wk. CK activities were significantly lower after the BCAA trial than in the PLAC trial at 4, 24, and 48 h postexercise, as well as lower than the CHO beverage at 24 h postexercise. CK was lower in the CHO trial at the 24- and 48-h time points than in the PLAC trial. LDH activities were lower in the BCAA trial at 4 h than in the PLAC trial. As compared with the CHO and PLAC trials, ratings of perceived soreness were lower at 24 h postexercise, and leg-flexion torque was higher at the 48-h time point after the BCAA trial. The present data suggest that BCAA supplementation attenuates muscle damage during prolonged endurance exercise in untrained college-age men. CHO ingestion attenuates CK activities at 24 and 48 h postexercise as compared with a placebo beverage.
本研究的目的是确定与等热量的碳水化合物（CHO）饮料或无热量的安慰剂（PLAC）饮料相比，补充支链氨基酸（BCAA）是否能减轻耐力运动期间肌肉损伤的间接指标。九名未经训练的男性以55%的最大摄氧量（VO₂peak）进行了三次90分钟的骑行运动。受试者对饮料选择不知情，在运动前和运动60分钟时通过CHO或BCAA饮料摄入总共200千卡能量，或者饮用PLAC饮料。在运动前、运动后即刻、4小时、24小时和48小时评估肌酸激酶（CK）、乳酸脱氢酶（LDH）、等速腿部伸展和屈曲扭矩以及肌肉酸痛情况。试验间隔8周。运动后4小时、24小时和48小时，BCAA试验后的CK活性显著低于PLAC试验，并且在运动后24小时低于CHO饮料。在24小时和48小时时间点，CHO试验中的CK低于PLAC试验。在运动后4小时，BCAA试验中的LDH活性低于PLAC试验。与CHO和PLAC试验相比，运动后24小时的肌肉酸痛感知评分较低，并且在BCAA试验后48小时时间点腿部屈曲扭矩较高。目前的数据表明，补充BCAA可减轻未受过训练的大学年龄男性在长时间耐力运动期间的肌肉损伤。与安慰剂饮料相比，摄入CHO可减轻运动后24小时和48小时的CK活性。
