An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise

This study was designed to determine the response of muscle protein to the bolus ingestion of a drink containing essential amino acids and carbohydrat e after resistance exercise. Six subjects (3 men, 3 women) randomly consume d a treatment drink (6 g essential amino acids, 35 g sucrose) or a flavored placebo drink Ih or 3 h after a bout of resistance exercise an two separat e occasions. We used a three-compartment model for determination of leg mus cle protein kinetics. The model involves the infusion of ring-H-2(6)-phenyl alanine, femoral arterial and venous blood sampling, and muscle biopsies. P henylalanine net balance and muscle protein synthesis were significantly in creased above the predrink and corresponding placebo value (P < 0.05) when the drink was taken 1 or 3 h after exercise but not when the placebo was in gested at 1 or 3 h. The response to the amino acid-carbohydrate drink produ ced similar anabolic responses at 1 and 3 h. Muscle protein breakdown did n ot change in response to the drink. We conclude that essential amino acids with carbohydrates stimulate muscle protein anabolism by increasing muscle protein synthesis when ingested 1 or 3 h after resistance exercise.