Related Experiment Videos
Creatine supplementation increases muscle total creatine but not maximal intermittent exercise performance
M J McKenna1, J Morton, S E Selig
1Department of Human Movement, Recreation, and Performance, Centre for Rehabilitation, Exercise, and Sports Science, Victoria University of Technology, Melbourne, Victoria 8001, Australia. michael.mckenna@vu.edu.au
Journal of Applied Physiology (Bethesda, Md. : 1985)
|December 22, 1999
Summary
Creatine supplementation increased muscle creatine stores but did not enhance intermittent sprinting performance. Muscle creatine levels returned to baseline after a washout period, with no lasting performance benefits observed.
Area of Science:
- Exercise Physiology
- Nutritional Biochemistry
- Sports Science
Background:
- Creatine supplementation is popular among athletes for enhancing performance.
- Understanding the time course of muscle creatine changes and their impact on performance is crucial.
Purpose of the Study:
- To investigate the effects of creatine supplementation on muscle total creatine (TCr) and creatine phosphate (CrP).
- To examine the impact of creatine supplementation on intermittent sprinting performance.
- To analyze the time course of muscle creatine changes, including the washout period.
Main Methods:
- Double-blind, placebo-controlled study with two groups (creatine vs. placebo).
- Volunteers ingested either creatine or dextrose for 5 days.
- Muscle biopsies and maximal cycle ergometer sprints were conducted before and at intervals after supplementation.
Main Results:
- Creatine supplementation significantly increased muscle TCr and CrP at 0 and 2 weeks, returning to baseline by 4 weeks.
- No significant differences in peak power or cumulative work during intermittent sprints were found between creatine and placebo groups.
- Muscle creatine levels increased with supplementation but performance did not improve.
Conclusions:
- Creatine supplementation effectively increases muscle creatine and phosphocreatine stores.
- Despite elevated muscle creatine, intermittent sprinting performance was not enhanced by creatine supplementation in this study.
- The performance effects of creatine supplementation may be context-dependent or require different protocols.