The Effect of Mild Dehydration Induced by Heat and Exercise on Cognitive Function

Paul H. Falcone*, Chih-Yin Tai, Laura R. Carson, Jesse A. Gwinn, Tyler R. Mccann, Nick J. Loveridge and Jordan R. Moon

The Effect of Mild Dehydration Induced by Heat and Exercise on Cognitive Function.

Past studies have demonstrated cognitive impairment after dehydration, though results are not always consistent. Methodological differences may account for these discrepancies. Therefore, the purpose of the present study was to determine the effects of mild dehydration on various domains of cognitive function.

Water is an essential nutrient for many bodily systems and functions, such as regulation of body
temperature, lubrication of joints, and optimal cardiovascular function. Hydration is especially
important in sports and physical activity, due to prodigious perspiration. However, dehydration is a common problem since many athletic individuals do not hydrate properly. Evidence supports the idea that dehydration leads to decrements in physical performance.

One possible reason for the mixed results in the literature is that the methods for testing cognitive function are inconsistent among studies. Because there are many cognitive domains that contribute to cognitive function, some studies focused on specific domains. In many of the studies on athletic populations such as golfers, soccer players, and jockeys, the testing methods were sport-specific to determine the effects of dehydration on the cognitive aspect of their specific sport.

Task-specific outcomes are also seen among cognitive tests in military personnel. While sport-specific testing methods may be ideal for elite athletes, they may not serve recreational or amateur athletes who lack the necessary level of expertise. Conversely, many studies that tested a wider range of domains chose cognitive tests that may not be ideal for athletic individuals. Though reaction time has been included in many studies to date, researchers often focused on short- and long-term memory or employed tests. A combination of active dehydration via treadmill running and passive dehydration via sauna was employed to achieve dehydration.


Psychol Cogn Sci Open J. 2017; 3(1): 17-23. doi: 10.17140/PCSOJ-3-120