Influence of Hydration Level and Body Fluids on Exercise Performance in the Heat,

Abstract

During exercise in the heat, sweat output often exceeds water intake resulting in hypohydration which is defined as a body fluid deficit. This fluid deficit is comprised of water loss from both the intracellular and extracellular fluid compartments. Hypohydration during exercise causes a greater heat storage and reduces endurance in comparison to euhydration levels. The greater heat storage is attributed to a decreased sweating rate as well as a decreased cutaneous blood flow. These response decrements have been related to both plasma hyperosmolality and a plasma hypovolemia. Subject gender, acclimation state and aerobic fitness do not alter the hypohydration response. Hyperhydration, or body fluid excess, does not appear to provide a clear advantage during exercise-heat stress, but may delay the development of hypohydration.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1984
Accession Number
ADA139284

Entities

People

  • Aaron J. Young
  • K. B. Pandolf
  • Michael N. Sawka
  • R. P. Francesconi

Organizations

  • United States Army Research Institute of Environmental Medicine

Tags

Communities of Interest

  • Human Systems

DTIC Thesaurus Topics

  • Acclimatization
  • Angiotensin
  • Blood
  • Blood Volume
  • Body Fluid Compartments
  • Body Fluids
  • Body Temperature
  • Body Water
  • Body Weight
  • Cardiovascular Physiological Phenomena
  • Cellular Structures
  • Digestive System Processes
  • Heart Rate
  • Medical Personnel
  • Physiology
  • Sweat Glands
  • Thermal Stresses

Readers

  • Cardiovascular Physiology
  • Exercise and Sports Science.