Creatine supplementation enhances maximum voluntary isometric force and endurance capacity in resistance trained men

Acta Physiol Scand. 1998 Jul;163(3):279-87. doi: 10.1046/j.1365-201x.1998.00395.x.


The present study examined the hypothesis that creatine (Cr) supplementation can increase the performance of isometric exercise in subjects engaged in a strength training program. Ten male subjects were tested in three experimental trials 7 days apart (days 1, 8 and 15). In each trial the subjects' maximum voluntary force of contraction (MVC) was measured in both legs and isometric endurance capacity at 80, 60, 40 and 20% of MVC of their stronger leg (knee extensor group) was measured with a 4-min rest between contractions. Additionally, the subjects' isometric endurance capacity at 80% of MVC of their weaker leg was measured in 10 repeated bouts interspersed with 2-min rest. A double-blind cross-over design was adopted for administering Cr or placebo. Subjects were randomized into either the Cr-placebo (Group A: days 2-6: 10 g day-1 of Cr; days 9-13: 10 g day-1 of glucose polymers) or the placebo-Cr group (Group B reverse supplementation order). The daily diet was analysed, and urine samples from 24-h collections were subjected to Cr and creatinine analysis. In each subject, approximately 18 g (35%) of Cr was eliminated in the urine during the Cr supplementation period. MVC increased by about 10% (P < 0.01 in the weaker leg, P < 0.05 in the stronger leg) and body mass increased by 1.7 +/- 0.4 kg (2.3%, P < 0.01) and 1.8 +/- 0.3 kg (2.1%, P < 0.01) in groups A and B, respectively, after Cr supplementation, while energy intake and diet composition remained constant throughout the study. The subjects' endurance capacity increased (P < 0.05) in all the bouts after Cr supplementation. Muscle hypertrophy in response to Cr supplementation and weight training may explain the findings of the present study.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Body Weight / drug effects
  • Body Weight / physiology
  • Creatine / pharmacology*
  • Creatine / urine
  • Cross-Over Studies
  • Diet
  • Double-Blind Method
  • Humans
  • Isometric Contraction / drug effects*
  • Male
  • Physical Endurance / drug effects*
  • Physical Fitness / physiology*
  • Weight Lifting


  • Creatine