Exercise heart rate response to facial cooling

Abstract

The heart rate responses of physically untrained men to exercise with and without facial cooling were determined. Cold wind (10 degrees C, 6.5 m x s-1, or 2 degrees C, 6.5 m x s-1) was directed at the faces of the subjects during a 16 min bout of progressively intense exercise. The 10 degrees C wind resulted in a significantly (p less than 0.05) lowering of heart rate that appeared to be associated with a decline in forehead temperature at 4, 6, and 8 min of exercise. No differences were observed for blood pressure or rectal temperature. The significant (p less than 0.05) reduction in heart rate with the 2 degrees C cold wind did not appear to be associated with changes in facial temperature. The 2 degrees C wind also resulted in a persistent peripheral vasoconstriction (p less than 0.05). The results suggest that the heart rate response to facial cooling during exercise is mediated not through a reflex associated with increased stroke volume but rather via a central thermoregulatory response.