Citation

Weller AS, Millard CE, Stroud MA, Greenhaff PL, Macdonald IA. Am. J. Physiol. 1997; 272(1 Pt 2): R226-33.

Affiliation

Department of Physiology and Pharmacology, University of Nottingham Medical School, Queen's Medical Centre, United Kingdom.

Copyright

(Copyright © 1997, American Physiological Society)

DOI

unavailable

PMID

9039013

Abstract

The potentially deleterious influence of body cooling on the thermoregulatory and metabolic responses to prolonged walking exercise has not been established. To address this problem, 10 men completed a 6-h intermittent (15 min rest, 45 min exercise) walking protocol in a thermoneutral (+15 degrees C) condition (Neutral) and a cold (+5 degrees C), wet, and windy condition (Cold). The first two exercise periods were conducted at a higher intensity (Higher, 6 km/h and 10% incline) than the subsequent four exercise periods (Lower, 5 km/h and 0% incline). Rectal temperature was lower and heart rate no different in Cold compared with Neutral, whereas the following were higher: oxygen consumption, respiratory exchange ratio, plasma norepinephrine and epinephrine, and blood lactate and glucose. There was no environmental influence on these variables during Higher. In conclusion, heat production during Lower was not sufficient to offset heat loss to the cold environment, and the resulting reduction in rectal temperature and metabolic perturbations may be detrimental if exercise is prolonged.

Language: en