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 [...]

Without adequate hydration, profound heat stress and dehydration can occur in people who work in hot environments. This study evaluated the effectiveness of three beverages on temperature regulation, cardiovascular response, and work performance during 60 h of dry heat exposure. Volunteer subjects lived in a climatic chamber in simulated desert conditions varying from 25-45 degrees [...]

This investigation evaluated the new National Collegiate Athletic Association model of heat acclimatization for football players using physiological, psychological, fluid balance, anthropometric, and nutritional variables. Eleven football players (20 +/- 1 year, 1.88 +/- 0.05 m, and 115.36 +/- 18.85 kg) from a Division I football team were observed for the first 8 days of [...]

The purpose of this investigation was to examine the combined effects of hydration and exercise heat stress on choice reaction time. On three separate occasions eight male subjects performed cycle exercise at approximately 70% of peak power output in warm, humid conditions (31 degrees C, 63% relative humidity) for a maximum of 90 min or [...]

BACKGROUND: Numerous laboratory based studies have documented that aggressive hydration strategies (approximately 1-2 litres/h) are required to minimise a rise in core temperature and minimise the deleterious effects of hyperthermia on performance. However, field data on the relations between hydration level, core body temperature, and performance are rare. OBJECTIVE: To measure core temperature (Tcore) in [...]

BJECTIVES: To determine changes in common urinary markers of hydration maintained by the drivers (mushers) during a wilderness endurance event in the arctic and to determine water turnover in this select group of individuals. STUDY DESIGN: During this descriptive study, data was systematically collected on hydration, water turnover, changes in resting and exercise heart rate, [...]

The aim of the present study was to investigate the effect of manipulating the provision of sports drink during soccer-specific exercise on metabolism and performance. Soccer players (N = 12) performed a soccer-specific protocol on three occasions. On two, 7 mL/kg carbohydrate-electrolyte (CHOv) or placebo (PLA) solutions were ingested at 0 and 45 min. On [...]

Early human ancestors evolved hunting in the midday heat on the dry African savannah and developed favourable biological adaptations that permit prolonged running in the heat. These physiological adaptations must have included the capacity to sweat profusely to maintain a low body temperature when running for 4-6 hours in dry heat, an absence of adverse [...]