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

J Appl Physiol (1985). 2000 Feb;88(2):386-92. doi: 10.1152/jappl.2000.88.2.386.


This study was designed to determine the response of muscle protein to the bolus ingestion of a drink containing essential amino acids and carbohydrate after resistance exercise. Six subjects (3 men, 3 women) randomly consumed a treatment drink (6 g essential amino acids, 35 g sucrose) or a flavored placebo drink 1 h or 3 h after a bout of resistance exercise on two separate occasions. We used a three-compartment model for determination of leg muscle protein kinetics. The model involves the infusion of ring-(2)H(5)-phenylalanine, femoral arterial and venous blood sampling, and muscle biopsies. Phenylalanine net balance and muscle protein synthesis were significantly increased 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 ingested at 1 or 3 h. The response to the amino acid-carbohydrate drink produced similar anabolic responses at 1 and 3 h. Muscle protein breakdown did not 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.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Administration, Oral
  • Amino Acids, Essential / administration & dosage
  • Amino Acids, Essential / pharmacology*
  • Analysis of Variance
  • Carbohydrates / administration & dosage
  • Carbohydrates / pharmacology*
  • Dietary Supplements
  • Exercise / physiology*
  • Female
  • Femoral Artery / drug effects
  • Femoral Artery / metabolism
  • Femoral Vein / drug effects
  • Femoral Vein / metabolism
  • Humans
  • Insulin / blood
  • Leg / blood supply
  • Male
  • Muscle Proteins / drug effects*
  • Muscle Proteins / metabolism
  • Phenylalanine / drug effects
  • Phenylalanine / metabolism
  • Regional Blood Flow / drug effects
  • Time Factors


  • Amino Acids, Essential
  • Carbohydrates
  • Insulin
  • Muscle Proteins
  • Phenylalanine