Journal of Applied Physiology, Vol 77, Issue 5 2214-2218, Copyright © 1994 by American Physiological Society

ARTICLES

Effect of exercise on cold tolerance and metabolic heat production in adult and aged C57BL/6J mice

O. Shechtman and M. I. Talan
Laboratory of Behavioral Sciences, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224.

Two groups of adult (12-mo-old) and two groups of aged (24-mo-old) C57BL/6J male mice were subjected to a standardized cold stress test (3-h partial restraint at 6 degrees C). One group from each age group was tested in the morning, and the other was tested in the afternoon. Half of the mice were subjected to running exercise on a treadmill during 1 h before the cold stress test. The other half were placed on a nonoperational treadmill for 1 h before the cold stress test. One hour of exercise resulted in improvement of cold tolerance during the subsequent cold exposure in both age groups but only during afternoon testing. Improvement in cold tolerance was not accompanied by an elevation of cold-induced metabolic heat production in adult mice. Metabolic heat production in aged mice showed only modest elevation. The discrepancy between improvement in cold tolerance and lack of elevation of metabolic heat production suggests that the primary mechanism for augmentation of cold tolerance after exercise in the afternoon is an improvement in cold-induced vasoconstriction of skin vessels, which is probably normally compromised in the afternoon.

This article has been cited by other articles:

				G. P. Kenny, A. A. Chen, B. A. Nurbakhsh, P. M. Denis, C. E. Proulx, and G. G. Giesbrecht Moderate exercise increases postexercise thresholds for vasoconstriction and shivering J Appl Physiol, October 1, 1998; 85(4): 1357 - 1361. [Abstract] [Full Text] [PDF]

				M. FLOREZ-DUQUET and R. B. McDONALD Cold-Induced Thermoregulation and Biological Aging Physiol Rev, April 1, 1998; 78(2): 339 - 358. [Abstract] [Full Text] [PDF]