Effects of an Amino Acid–Carbohydrate Drink on Exercise Performance after Consecutive-Day Exercise Bouts

Abstract

This study examined the effect of amino acids in a carbohydrate beverage on cycling performance. Twelve male athletes (28.5 +/- 2.1 yr) cycled at 75% VO2peak for 90 min followed by a ride to exhaustion at 85% VO2peak, before (T1) and on 2 consecutive days (T2 and T3) after 2 weeks of supplementation with 3.6% carbohydrate plus 1% amino acids (AA) or 4.6% carbohydrate-only (CHO) isocaloric beverages. Muscle damage was assessed by plasma creatine kinase (CK), and muscle fatigue by changes in vertical jump pre- to postexercise. Muscle soreness, overall fatigue, and changes in mood state were assessed using questionnaires. Plasma CK was lower for AA in T3 (214.0 +/- 13.5 vs. 485.9 +/- 191.4 U/L immediately post, 213.9 +/- 13.1 vs. 492.0 +/- 199.4 U/L 5 hr post, and 194.9 +/- 17.9 vs. 405.9 +/- 166.6 U/L 24 hr postexercise in AA and CHO, respectively). Time to exhaustion decreased from T2 to T3 only in CHO (10.9 +/- 2.5 to 12.6 +/- 3.2 vs. 13.8 +/- 2.8 to 7.8 +/- 1.5 min in AA and CHO, respectively). Vertical-jump change from pre- to postexercise was greater in T3 for the CHO treatment. Total fatigue score and mood disturbance decreased significantly only with AA in T3. The addition of AA to a carbohydrate beverage after consecutive-day exercise bouts reduced muscle damage as indicated by CK levels, decreased fatigue, and maintained exercise performance compared with consuming carbohydrate alone.

Branched-Chain Amino Acid Supplementation Increases the Lactate Threshold during an Incremental Exercise Test in Trained Individuals

“…Therefore, the addition of arginine to BCAA supplements is expected to enhance the anabolic effect of BCAA by increasing protein synthesis (25) and decreasing protein breakdown (26), and the combination of BCAA and arginine is therefore used as nutritional supplements for athletes. Recently the supplementation of BCAA with arginine during endurance exercise has been reported to suppress muscle protein breakdown (16), suppress an increase in the plasma lactate dehydrogenase/creatine kinase activity (27,28), and also suppress a decrease in the exercise performance caused by muscle damage (28). Therefore, the supplementation of BCAA with arginine is considered to be potentially effective for athletes to preserve skeletal muscle mass and muscle functions.…”

Co-ingestion of carbohydrate and pea protein does not enhance muscle recovery after strenuous exercise

“…Muscle recovery can be evaluated by several parameters such as plasma LDH and CK or even isometric strength, all investigated in this study, concerning the influence of the different types of supplementation administered immediately after the exercise period. According to previous studies, CK and LDH measurements in 24-hour post-exercise have a practical relevance 13,22 providing basis for the use of such analysis in this work.…”

Effects of protein and amino acid supplementation on muscle protein metabolism in relation to exercise

“…This effect has also been demonstrated in male subjects 32) . Furthermore, it has been reported that BCAA supplementation reduces exercise-induced muscle damage and improves exercise performance in the successive exercise program of athletes under fatigue conditions 33) . These findings support the notion that BCAA supplementation is useful for sports, although the Physiological effects of BCAA supplementation on skeletal muscles…”