Thermoregulatory and metabolic responses to repeated bouts of prolonged cycle-ergometer exercise in man

Acta Physiol Pol. 1990 Nov-Dec;41(7):22-31.


Changes in body temperature, oxygen uptake (VO2), heart rate (HR), sweating rate and plasma osmolarity were examined in 10 human subjects, performing four successive 30 min exercise-bouts of the same intensity (50% VO2 max) separated by 30 min rest periods. In spite of the rest intervals and replacement of body fluid loss there was a progressive increase in VO2. HR, rectal (Tre) and mean body (Tb) temperatures in consecutive exercise bouts. The thermoregulatory efficiency showed an increasing tendency, and a delay in the sweating response at the beginning of each exercise was shortened. It is concluded that a drift in metabolic and temperature responses to exercise, reported throughout a long-term continuous work, occurs also in the euhydrated subjects performing a prolonged intermittent exercise. It is not caused by an impaired thermoregulation during exercise but rather by insufficient restitution of metabolic processes during rest intervals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Temperature / physiology
  • Body Temperature Regulation / physiology*
  • Energy Metabolism / physiology*
  • Exercise / physiology*
  • Exercise Test*
  • Heart Rate / physiology
  • Humans
  • Male
  • Osmolar Concentration
  • Oxygen Consumption / physiology
  • Skin Temperature / physiology
  • Sweating / physiology
  • Time Factors
  • Ventilation-Perfusion Ratio