Devolve, K. L., Davis, J. M., Alderson, N. L., Welsh, R. S., Russell, B. K., & Walters, J. J. (1997). Effects of carbohydrate and branch-chain amino acid ingestion on intermittent, high intensity running. Medicine and Science in Sports and Exercise, 29(5), Supplement abstract 720.

Branched chain amino acid (BCAA) supplementation has been suggested as having the potential to delay fatigue during prolonged exercise. However, its effect has not been measured in intermittent, high-intensity activities (e.g., soccer, rugby).

Ss (N = 8) performed 5 x 15 min sessions of shuttle running (intervals of walking, sprinting, and running at 55% and 95% VO2max) followed by intermittent running at 55 and 95% VO2max to fatigue. Treatments consisted of:

• flavored water as a placebo,
• CHO one hour before (5 ml/kg; 18%),
• immediately before and during exercise (2 ml/kg; 6%), and
• CHO+BCAA (7 gm) at one hour and immediately before exercise.

Ss ran longer when fed either CHO or CHO+BCAA. Both conditions had higher glucose and lower free fatty acid concentrations than the placebo condition.

BCAA did not seem to benefit performance in this type of exercise.

Implication. Drinking CHO solutions one hour before and during exercise improves intermittent performance capacity. The addition of BCAA does not enhance or add to the CHO effect.

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