PRIOR HEAT STRESS: EFFECT ON SUBSEQUENT 15-MIN TIME TRIAL PERFORMANCE IN THE HEAT.

The impact of prior heat stress on subsequent aerobic exercise-heat performance has not been studied. PURPOSE: To determine whether prior heat stress degrades subsequent aerobic exercise performance in the heat. METHODS: Eighteen nonheat acclimated males were trained (four practice trials) on an aerobic exercise performance test in 22 degrees C and then divided into two [...]

By |2013-01-31T18:34:07+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

THE EFFECT OF FLUID REPLACEMENT ON ENDURANCE PERFORMANCE

The purpose of this study was to examine the effects of fluid replacement on power output (PO), rating of perceived exertion (RPE), heart rate (HR), body weight (BW), urine osmolarity (Uosm), and urine electrolyte concentrations ([UNa+], [UK+], [UCl-]) in physically active men (n = 4) and women (n = 7). The participants were asked to [...]

By |2013-01-31T18:34:07+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

DEHYDRATION IMPAIRS VIGILANCE-RELATED ATTENTION IN MALE BASKETBALL PLAYERS

PURPOSE: To determine the effects of dehydration (DEH) on attentional vigilance in male basketball players. METHODS: The Test of Variables of Attention (TOVA; Universal Attention Disorders) was administered to 11 male basketball players (17-28 yr) at baseline (test 1), after walking (50% V O2max) in the heat (40 degrees C and 20% relative humidity) (test [...]

By |2013-01-31T18:34:07+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

THERMOREGULATION AND MARATHON RUNNING: BIOLOGICAL AND ENVIRONMENTAL INFLUENCES

The extreme physical endurance demands and varied environmental settings of marathon footraces have provided a unique opportunity to study the limits of human thermoregulation for more than a century. High post-race rectal temperatures (Tre) are commonly and consistently documented in marathon runners, yet a clear divergence of thought surrounds the cause for this observation. A [...]

By |2013-01-31T18:34:07+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

COMPARISON OF SWEAT LOSS ESTIMATES FOR WOMEN DURING PROLONGED HIGH-INTENSITY RUNNING

PURPOSE: This study evaluated the error produced by four commonly used field estimates and two prediction equations of total body sweat loss. METHODS: Eight women distance runners were studied during a 30-km treadmill run (approximately 70% .VO(2max)) in a warm (30 degrees C T(db)) and a cool (14 degrees C T(db)) environment. Total sweat loss [...]

By |2013-01-31T18:34:07+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

DEHYDRATION MARKEDLY IMPAIRS CARDIOVASCULAR FUNCTION IN HYPERTHERMIC ENDURANCE ATHLETES DURING EXERCISE

We identified the cardiovascular stress encountered by superimposing dehydration on hyperthermia during exercise in the heat and the mechanisms contributing to the dehydration-mediated stroke volume (SV) reduction. Fifteen endurance-trained cyclists [maximal O2 consumption (VO2max) = 4.5 l/min] exercised in the heat for 100-120 min and either became dehydrated by 4% body weight or remained euhydrated [...]

By |2013-01-31T18:34:06+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

COMPARISON OF WATER TURNOVER RATES IN MEN UNDERTAKING PROLONGED CYCLING EXERCISE AND SEDENTARY MEN

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 [...]

By |2013-01-31T18:34:06+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

EFFECTS OF GLYCEROL-INDUCED HYPERHYDRATION PRIOR TO EXERCISE IN THE HEAT ON SWEATING AND CORE TEMPERATURE

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 [...]

By |2013-01-31T18:34:06+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

EFFECT OF OVERHYDRATION ON TIME-TRIAL SWIM PERFORMANCE

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, [...]

By |2013-01-31T18:34:06+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments