The influence of dietary creatine supplementation on performance during repeated bouts of maximal isokinetic cycling in man
- 744 Downloads
The effect of dietary creatine (Cr) supplementation on performance during 3, 30 s bouts maximal isokinetic cycling and on plasma ammonia and blood lactate accumulation during exercise was investigated. Placebo (P) ingestion had no effect on peak power output (PPO), mean power output (MPO) and total work output during each bout of exercise. Cr ingestion (4 × 5 g.day−1 for 5 days) significantly increased PPO in exercise bout 1 (p<0.05) and IMO and total work output in exercise bouts 1 (p<0.05, p<0.05, respectively) and 2 (p<0.05, p<0.05, respectively). Cr ingestion had no effect on any of the measures of performance during exercise bout 3. No difference was observed in peak plasma ammonia accumulation before (146 + 30 μmol.l−1) and after (122 ±17 μmol.l−1) P ingestion, however the corresponding concentration was lower following Cr ingestion (129 ± 22 μmol.l−1) compared with before Cr ingestion (160 ± 18 μmol.l−1, p<0.05), despite subjects performing more work. No difference in peak blood lactate accumulation was observed before and after P or Cr ingestion. The results demonstrate that Cr ingestion can increase whole body exercise performance during the initial two, but not a third, successive bout of maximal exercise lasting 30 s. The lower accumulation of plasma ammonia under these conditions suggests this response is achieved by an effect on muscle ATP turnover.
Key wordsExercise Recovery ATP Phosphocreatine Fatigue
Unable to display preview. Download preview PDF.
- Balsom PD, Eklblom B, Soderlund K, Sjodin B, Hultman E (1993). Creatine supplementation and dynamic high-intensity intermittent exercise. Scand J Med Sci Sports, 3: 143–149.Google Scholar
- Bessman SP, Savabi F (1990). The role of the phosphocreatine energy shuttle in exercise and muscle hypertrophy. In: Taylow AW, Gollnick PD, Green HJ, Ianuzzo CD, Noble EG, Metivier G, Sutton JR (eds) Biochemistry of Exercise VII, Human Kinetics Publishers, Champaign, IL, USA, pp167–178Google Scholar
- Greenhaff PL, Constantin-Teodosiu D, Casey A, Hultman E (1994b). The effect of oral creatine supplementation on muscle ATP degradation during repeated bouts of maximal voluntary exercise in man. J Physiol, 478: 84P.Google Scholar
- Harris RC, Marlin DJ, Snow DH, Harkness RA (1991). Muscle ATP loss and lactate accumulation at different work intensities in the exercising Thoroughbred horse. Eur J Appl Physiol, 62: 235–244.Google Scholar
- Hultman E, Bergstrom M, Spriet LL, Soderlund K (1990). Energy metabolism and fatigue. In: Taylow AW, Gollnick PD, Green HJ, Ianuzzo CD, Noble EG, Metivier G, Sutton JR (eds) Biochemistry of Exercise VII, Human Kinetics Publishers, Champaign, IL, USA, pp 73–92.Google Scholar