PURPOSE: Although many studies have attempted to examine the effect of hypohydration on strength, power, and high-intensity endurance, few have successfully isolated changes in total body water from other variables that alter performance (e.g., increased core temperature), and none have documented the influence of hypohydration on an isotonic, multiset, multirepetition exercise bout typical of resistance [...]
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 [...]
Significant scientific evidence documents the deleterious effects of hypohydration (reduced total body water) on endurance exercise performance; however, the influence of hypohydration on muscular strength, power and high-intensity endurance (maximal activities lasting >30 seconds but
Bioelectrical impedance analysis (BIA) has been suggested as a simple, rapid method to assess changes in hydration status. BIA measures the electrical impedance to a low amperage current that is affected by both water and electrolyte content of the body. While BIA can reliably estimate total body water and body density in euhydrated individuals under [...]
This study examined the effects of beverage composition on the voluntary drinking pattern, body fluid balance and body temperature responses of heat-acclimatized trained girls exercising intermittently in outdoor conditions (WBGT = 30.9 +/- 0.2 degrees C). Twelve trained, heat-acclimatized girls (age = 10.6 +/- 0.2 years) performed three 3-h sessions, each consisting of four 20-min [...]
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 [...]
Eighty-six children in Florida died of complications associated with diarrhea between 1985 and 1990, deaths which constituted an important preventable fraction of infant mortality. The state will support health professionals in reducing the number of hospitalizations and deaths due to diarrheal complications, Governor Lawton Chiles announced in September 1991, and the Florida Department of Health [...]
This paper compares the hydration ability of three commercially-available sports drinks with water under conditions of rest and exercise, using a deuterium dilution technique. For the rest group, 0.05g/kg of body weight of deuterium, contained in gelatine capsules, was ingested with one of the test solutions and saliva samples were collected every five minutes for [...]
No abstract available.
Caffeine is regarded as a diuretic despite evidence that hydration is not impaired with habitual ingestion. The purpose of this study was to determine whether a caffeinated sports drink impairs fluid delivery and hydration during exercise in warm, humid conditions (28.5 degrees C, 60% relative humidity). Sixteen cyclists completed 3 trials: placebo (P), carbohydrate-electrolyte (CE), [...]