Some athletes and trainers are reluctant to use creatine because of concerns related to side effects. Since creatine accumulates in muscle and drags some water along with it, there is concern that dehydration may result and lead to heat stress and other related problems such as muscle cramping.
A recent comprehensive review of creatine supplementation studies tried to determine if these concerns were justified. A total of 10 studies were identified that assessed the effects of creatine supplementation on thermoregulation and hydration status. The authors concluded that creatine supplementation was not associated with any detrimental effects of creatine on body temperature regulation, dehydration, urine hydration measures, plasma volume or sweat loss. This is consistent with previous work conducted on creatine supplementation that showed normal responses to exercising in the heat. In fact, creatine supplementation actually increased performance in the heat similar to other studies performed at normal temperatures.
Thus, creatine supplementation is safe and can be used to enhance high intensity performance in athletes exercising in hot environments without concern of heat-related illness.