Exercise intensity powerfully influences testosterone, cortisol, and testosterone : cortisol ratio (T:C) responses to endurance exercise. Hydration state may also modulate these hormones, and therefore may alter the anabolic/catabolic balance in response to endurance exercise and training. This study examined the effect of running intensity on testosterone, cortisol, and T : C when exercise was [...]

The purpose of this study was to examine the thermoregulatory sweating control parameters of threshold temperature and sensitivity to determine whether 1) these variables were altered by hypohydration level and exercise intensity and 2) these alterations, if present, were additive and independent. Nine heat-acclimated men completed a matrix of nine trials: three exercise intensities of [...]

During exercise in the heat, sweat output often exceeds water intake, resulting in hypohydration, which is defined as a body fluid deficit. This fluid deficit is comprised of water loss from both the intracellular and extracellular fluid compartments. Hypohydration during exercise causes a greater heat storage and reduces endurance in comparison with euhydration levels. The [...]

Hypohydration (decreased total body water) exacerbates the catabolic hormonal response to endurance exercise with unclear effects on anabolic hormones. Limited research exists that evaluates the effect of hypohydration on endocrine responses to resistance exercise; this work merits attention as the acute postexercise hormonal environment potently modulates resistance training adaptations. The purpose of this study was [...]

Fluid replacement remains an important strategy for preserving exercise performance as dehydration in excess of 2% of body weight consistently impairs aerobic exercise performance. Too much of a good thing, however, can have negative health consequences as persistent drinking in excess of sweating rate can induce symptomatic exercise associated hyponatremia. This short review highlights new [...]

The performance of both physical and mental tasks can be adversely affected by heat and by dehydration. There are well-recognized effects of heat and hydration status on the cardiovascular and thermoregulatory systems that can account for the decreased performance and increased sensation of effort that are experienced in the heat. Provision of fluids of appropriate [...]

Various reports indicate that humans receive 20-25% of their daily water intake from food. Fruits, vegetables and other high-moisture foods, therefore, make an important contribution to total fluid intake. In addition, co-ingestion of other nutrients and ingredients can impact drinking behavior, absorption, distribution and retention of water, all of which contribute to the person's hydration [...]

There is a rich scientific literature regarding hydration status and physical function that began in the late 1800s, although the relationship was likely apparent centuries before that. A decrease in body water from normal levels (often referred to as dehydration or hypohydration) provokes changes in cardiovascular, thermoregulatory, metabolic, and central nervous function that become increasingly [...]

As a result of exercise-induced sweating, athletes and trained individuals can lose up to 3 L of fluid per hour. Fluid replacement is required to maintain hydration and allow the athlete to continue to perform. Inadequate fluid intake will adversely affect temperature regulation, cardiovascular function, and muscle metabolism. To maximize fluid intake and effectively replace [...]

It is the position of the American College of Sports Medicine that adequate fluid replacement helps maintain hydration and, therefore, promotes the health, safety, and optimal physical performance of individuals participating in regular physical activity. This position statement is based on a comprehensive review and interpretation of scientific literature concerning the influence of fluid replacement [...]