Journal of Applied Physiology

Creatine supplementation influences substrate utilization at rest

M. Erik Huso, Jeffrey S Hampl, Carol S. Johnston, Pamela D. Swan


The influence of creatine supplementation on substrate utilization during rest was investigated using a double-blind crossover design. Ten active men participated in 12 wk of weight training and were given creatine and placebo (20 g/day for 4 days, then 2 g/day for 17 days) in two trials separated by a 4-wk washout. Body composition, substrate utilization, and strength were assessed after weeks 2, 5, 9, and 12. Maximal isometric contraction [1 repetition maximum (RM)] leg press increased significantly (P < 0.05) after both treatments, but 1-RM bench press was increased (33 ± 8 kg, P < 0.05) only after creatine. Total body mass increased (1.6 ± 0.5 kg, P < 0.05) after creatine but not after placebo. Significant (P < 0.05) increases in fat-free mass were found after creatine and placebo supplementation (1.9 ± 0.8 and 2.2 ± 0.7 kg, respectively). Fat mass did not change significantly with creatine but decreased after the placebo trial (−2.4 ± 0.8 kg, P < 0.05). Carbohydrate oxidation was increased by creatine (8.9 ± 4.0%,P < 0.05), whereas there was a trend for increased respiratory exchange ratio after creatine supplementation (0.03 ± 0.01, P = 0.07). Changes in substrate oxidation may influence the inhibition of fat mass loss associated with creatine after weight training.

  • substrate oxidation
  • respiratory exchange ratio
  • carbohydrate
  • phosphate


  • Address for reprint requests and other correspondence: J. S Hampl, Dept. of Nutrition, Arizona State University, 7001 E. Williams Field Rd., Mesa, AZ 85212.

  • The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

  • August 16, 2002;10.1152/japplphysiol.01170.2001

View Full Text