Human Physiological Responses to a Standardized Cold Stress as Modified by Physical Fitness

¹ From the Arctic Aeromedical Laboratory, APO 731, Seattle, Washington

The effects of a standardized cold stress were measured on five adult, male Caucasian volunteers before and after an extended physical training program designed to increase the levels of physical fitness. Rectal, average skin and extremity temperatures and whole body metabolic rates were determined at 5-minute intervals throughout a 1-hour exposure of the nude subjects to an ambient temperature of 50°F (10°C). Physical fitness scores were measured, using a treadmill to ascertain the efficacy of a 3-week physical training program between the cold room exposures. After the physical training program, during which physical fitness levels were significantly increased, average levels of heat production were 15 Cal/hr/m² higher, mean rectal temperatures were 0.5°C lower, average skin temperatures 1.0°C higher and foot and toe temperatures 3.0 and 4.0°C higher, respectively, with no significant differences in average body temperatures throughout the cold room exposures. These data indicate that many of the currently accepted indices of cold acclimatization may be produced by changing levels of physical fitness alone.

This article has been cited by other articles:

				F. De Lorenzo, V. Sharma, M. Scully, and V.V. Kakkar Cold adaptation and the seasonal distribution of acute myocardial infarction QJM, December 1, 1999; 92(12): 747 - 751. [Full Text] [PDF]

				W. D. van Marken Lichtenbelt, P. Schrauwen, S. van de Kerckhove, and M. S. Westerterp-Plantenga Individual variation in body temperature and energy expenditure in response to mild cold Am J Physiol Endocrinol Metab, May 1, 2002; 282(5): E1077 - E1083. [Abstract] [Full Text] [PDF]