ABSTRACT
Water is an essential component of the human body, comprising 55-60 percent of total body weight in adults and up to 75 percent of total body weight in children and infants. Water is required for thermoregulation and cellular function, and is critical for life. Mild levels of dehydration (approximately 2 percent loss of body weight) produce alterations in mood and cognitive performance as well as disruptions in physical performance (Popowski et al. 2001). The impact of underhydration and hydration in physical activity, particularly in athletes and in the military, has been of considerable interest and is well described in the scientiŠc literature (Maughan et al. 2007; Murray 2007; Sawka and Noakes 2007). What remains less well understood is the relationship between hydration and brain function. A number of early studies indicate that water loss in hot climates and under conditions of vigorous physical activity produces signiŠcant decrements in cognitive performance (D’Anci 2005 ; Popkin et al. 2010). However, in comparison to earlier reports, results of studies published more recently have shown milder effects of hydration status on cognitive function (Popkin et al. 2010). Even though deŠnitive conclusions have yet to be made, there is evidence that mild levels of dehydration can lead to alterations in cognitive function and disruptions in subjective mood.
