REVIEW: EXERCISE, HEAT, HYDRATION AND THE BRAIN

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 [...]

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

NATIONAL ATHLETIC TRAINERSA’ ASSOCIATION POSITION STATEMENT: FLUID REPLACEMENT FOR ATHLETES

OBJECTIVE: To present recommendations to optimize the fluid-replacement practices of athletes. BACKGROUND: Dehydration can compromise athletic performance and increase the risk of exertional heat injury. Athletes do not voluntarily drink sufficient water to prevent dehydration during physical activity. Drinking behavior can be modified by education, increasing accessibility, and optimizing palatability. However, excessive overdrinking should be [...]

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

FLUID BALANCE AND ENDURANCE EXERCISE PERFORMANCE

Dehydration alters cardiovascular, thermoregulatory, central nervous system, and metabolic functions. One or more of these alterations will degrade endurance exercise performance when dehydration exceeds 2% of body weight. These performance decrements are accentuated by heat stress. To minimize the adverse consequences of body water deficits on endurance exercise performance, it is recommended that fluid intake [...]

By |2013-01-31T18:34:06+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