Total body water (TBW) and water turnover rates (WTR) of six competitive male cyclists (CG) and six age-matched sedentary men (SG) were determined using deuterium oxide dilution and elimination. During the 7 day study, individuals in the CG cycled daily outside on average 50 (range 12-146) km at an average speed of 29 km.h(-1), while [...]
Hypohydration reduces exercise performance and thermoregulatory capacity in the heat. Hyperhydration prior to exercise may decrease, delay, or eliminate the detrimental effects of hypohydration. The rapid clearance of excess fluid makes hyperhydration of subjects with common beverages difficult. Glycerol, a natural metabolite which is rapidly absorbed, has osmotic action, and is evenly distributed within the [...]
The effect of hydration status on performance has not been adequately emphasized or examined in swimmers. Theoretically, moderate overhydration might reduce the proportionate fluid loss from the circulation during exercise of this nature. To explore this issue, 11 (5 women, 6 men) collegiate swimmers swam 2 183-m (200-yd) time trials (3 days apart) in alternate, [...]
Dehydration and hyperthermia may impair gastric emptying (GE) during exercise; the effect of these alterations on intestinal water flux (WF) is unknown. Thus the purpose of this study was to determine the effect of hypohydration ( approximately 2.7% body weight) on GE and WF of a water placebo (WP) during cycling exercise (85 min, 65% [...]
This study determined the influence of exercise intensity, protective clothing level, and climate on physiological tolerance to uncompensable heat stress. It also compared the relationship between core temperature and the incidence of exhaustion from heat strain for persons wearing protective clothing to previously published data of unclothed persons during uncompensable heat stress. Seven heat-acclimated men [...]
The effect of different rates of fluid ingestion on heart rate, rectal temperature, plasma electrolytes, hormones and performance was examined during prolonged strenuous exercise conducted at 21 degrees C. Seven well-trained males (24 +/- 1 yr; 68.6 +/- 2.9 kg; VO2 peak = 4.69 +/- 0.17 L min-1; mean +/- SEM) cycled for 2 h [...]
No abstract available.
A variety of beverages formulated to provide fluid, carbohydrates, and electrolytes during and following exercise are commercially available. Such 'sport drinks' commonly contain 4 to 8% carbohydrate (as glucose, fructose, sucrose or maltodextrins) and small amounts of electrolytes (most often sodium, potassium, and chloride). The efficacy of consuming such beverages has been questioned primarily because [...]
The purpose of this study was to determine the effect of ingesting approximately 800, 1200, or 1600 ml.h-1 of a carbohydrate (CHO) solution on gastric emptying (GE), ratings of stomach fullness (RF), plasma volume changes (PVC), electrolytes, fluid loss, and blood glucose (BG) during 2 h of cycling at 70% of VO2max. Eight male cyclists [...]