Does creatine supplementation hinder exercise heat tolerance or hydration status? A systematic review with meta-analyses.
OBJECTIVE
To critically assess original research addressing the effect of creatine supplementation on exercise heat tolerance and hydration status.


METHODS
We searched the electronic databases PubMed, Scopus, Web of Science, SPORTDiscus, and Rehabilitation & Physical Medicine, without date limitations, for the following key words: creatine, exercise, thermoregulation, dehydration, hyperthermia, heat tolerance, exertional heat illnesses, and renal function. Our goal was to identify randomized clinical trials investigating the effect of creatine supplementation on hydration status and thermoregulation. Citations from related articles also were identified and retrieved.


RESULTS
Original research was reviewed using the Physiotherapy Evidence Database (PEDro) Scale. One author initially screened all articles. Fifteen of 95 articles examined the effects of creatine on thermoregulation or hydration status (or both). Two independent reviewers then reviewed these articles. Ten studies were selected on the basis of inclusion and exclusion criteria. The PEDro scores for the 10 studies ranged from 7 to 10 points (maximum possible score = 10 points).


CONCLUSIONS
No evidence supports the concept that creatine supplementation either hinders the body's ability to dissipate heat or negatively affects the athlete's body fluid balance. Controlled experimental trials of athletes exercising in the heat resulted in no adverse effects from creatine supplementation at recommended dosages.
Lopez
Rebecca M
RM
University of Connecticut, Storrs, CT 06269, USA. Rebecca.Lopez@uconn.edu
Casa
Douglas J
DJ
McDermott
Brendon P
BP
Ganio
Matthew S
MS
Armstrong
Lawrence E
LE
Maresh
Carl M
CM
D001833:Body Temperature Regulation / Q000187:drug effects* / Q000502:physiology; D003401:Creatine / Q000008:administration & dosage*; D003681:Dehydration / Q000517:prevention & control; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000187:drug effects* / Q000502:physiology; D005260:Female; D005334:Fever / Q000517:prevention & control; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D012016:Reference Values; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014882:Water-Electrolyte Balance / Q000187:drug effects* / Q000502:physiology
D003401:Creatine