McArthur, P. D., Webster, M. J., Boyd, J. C., May, R. A., Eschbach, L. C., Eimer, A. J., Angelopoulos, T. J., Zoeller, R. F., & Krebs, G. V. (1999). Creatine supplementation and acute dehydration. Medicine and Science in Sports and Exercise, 31(5), Supplement abstract 1276.

Numerous anecdotal reports suggest that creatine supplementation compromises heat tolerance during exercise, leading to an increase in skeletal muscle cramping and tearing. This study investigated the effects of oral creatine supplementation and acute dehydration on plasma volume, electrolyte and mineral balance, and anaerobic exercise performance. Ss ingested 20 g/day of creatine (N = 8) or placebo (N = 7) for five days and then undertook two consecutive 80-minute dehydration protocols resulting in 1.5% and ~3% decreases in body mass.

Both groups similarly increased body mass over the five-days. There were no significant changes in body composition, plasma volume, serum electrolytes, minerals, osmolality, and anaerobic maximum power, total work, or fatigue index. Dehydration caused significant plasma volume decreases in both groups.

Five days of creatine supplementation did not negatively affect plasma volume or serum electrolyte or mineral balance. Performance of repeated bouts of anaerobic exercise were not improved by the supplementation.

Implication. A five-day burst of creatine supplementation does not affect plasma volume or electrolyte/mineral balance or improve repeated anaerobic exercise performance.

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