Hypohydration has more consistently been proven to impair aerobic and high intensity endurance activities than muscular strength and cognitive activities. During exercise, as hypohydration reaches levels >3%, core temperature rise may be accentuated and pose health risks. This is of special concern in children and adolescents as well as older individuals who may be more susceptible to heat-related diseases, especially when exercise is performed in warm conditions. A fluid replacement plan is then necessary if hypohydration is expected due to intense sweating. Under some circumstances, ingestion of beverages, known as sports drinks, containing a proper mixture of electrolytes and carbohydrate have shown some benefits compared with plain water. Inclusion of other ingredients (caffeine, vitamins, taurine) has not been proven efficacious and may indeed cause adverse effects. Given the widespread consumption of these beverages, practical recommendations regarding their use, timing, and optimal composition are needed. © 2013 Elsevier Inc. All rights reserved.
