Hyperthermia and exercise

The paper emphasizes fluid and electrolyte parameters that affect the hyperthermia of physical exercise (metabolic heat production). The major hypothesis discussed is that fluid and electrolyte changes influence thermal regulation within the fine control boundaries. A second working hypothesis is that the elevation of core temperature during exercise is a regulated phenomenon that is beneficial to the organism in terms of efficiency and potential for survival and is not merely a failure of the thermoregulatory control system. The central thermoregulatory mechanism seems more responsive to the hypothermic effect of calcium than to the hyperthermic effect of sodium. The mechanisms controlling plasma fluid-electrolyte shifts, particularly during exercise and recovery from exercise, may play an important part in exercise thermoregulation.