Effects of an amino acid/creatine energy supplement on the acute hormonal response to resistance exercise

Int J Sport Nutr Exerc Metab. 2007 Dec;17(6):608-23. doi: 10.1123/ijsnem.17.6.608.


The authors aimed to examine the acute hormonal and performance responses to resistance exercise with and without prior consumption of an amino acid/creatine/energy supplement. Eight men performed a resistance-exercise protocol at baseline (BL), 20 min after consuming a supplement (S) consisting of essential amino acids, creatine, taurine, caffeine, and glucuronolactone or a maltodextrin placebo (P). Venous blood samples were obtained before and immediately after (IP), 15 min (15P), and 30 min (30P) after each protocol. Area under the curve of resistance-exercise volume revealed that BL was significantly less than S (10%) and P (8.6%). For fatigue rate, only S (18.4% +/- 12.0%) was significantly lower than BL (32.9% +/- 8.4%). Total testosterone (TT) and growth hormone (GH) were significantly elevated at IP and 15P in all conditions. The GH response was significantly lower, however, in S and P than in BL. The TT and GH responses did not differ between S and P. These results indicated that a supplement consisting of amino acids, creatine, taurine, caffeine, and glucuronolactone can modestly improve high-intensity endurance; however, the anabolic-hormonal response was not augmented.

Publication types

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

MeSH terms

  • Adult
  • Amino Acids / administration & dosage*
  • Area Under Curve
  • Creatine / administration & dosage*
  • Cross-Over Studies
  • Dietary Supplements
  • Double-Blind Method
  • Energy Intake / physiology*
  • Human Growth Hormone / blood*
  • Humans
  • Male
  • Testosterone / blood*
  • Weight Lifting / physiology*


  • Amino Acids
  • Human Growth Hormone
  • Testosterone
  • Creatine