Effect of body temperature on the ventilatory response to exercise

Abstract

The mechanisms by which pulmonary ventilation increases during exercise are poorly understood. It has been suggested that increasing body temperature may play an important role in the exercise hyperpnea. Eight subjects were studied at progressively increasing work rates to fatigue on two non-consecutive days. On one day the subjects were normothermic and on the other day the subjects were hypothermic during the control period of the exercise. Hypothermia was induced by a 90 minute cold shower (16 ±1 °C). The average reduction in body (rectal) temperature resulting from the cold shower was 1.1 °C. Metabolic responses to the test were similar whether the subject began the exercise in a normothermic or hypothermic state. Pulmonary ventilation during the tests increased in proportion to the level of CO 2 production and was independent of the level of body temperature. This suggests that body temperature is not an independent stimulus to ventilation during exercise.