Thermoregulation during cold exposure: effects of prior exercise.
J Appl Physiol (1985)
; 87(1): 247-52, 1999 Jul.
Article
in En
| MEDLINE
| ID: mdl-10409582
ABSTRACT
This study examined whether acute exercise would impair the body's capability to maintain thermal balance during a subsequent cold exposure. Ten men rested for 2 h during a standardized cold-air test (4.6 degrees C) after two treatments 1) 60 min of cycle exercise (Ex) at 55% peak O(2) uptake and 2) passive heating (Heat). Ex was performed during a 35 degrees C water immersion (WI), and Heat was conducted during a 38.2 degrees C WI. The duration of Heat was individually adjusted (mean = 53 min) so that rectal temperature was similar at the end of WI in both Ex (38.2 degrees C) and Heat (38.1 degrees C). During the cold-air test after Ex, relative to Heat 1) rectal temperature was lower (P < 0.05) from minutes 40-120, 2) mean weighted heat flow was higher (P < 0.05), 3) insulation was lower (P < 0.05), and 4) metabolic heat production was not different. These results suggest that prior physical exercise may predispose a person to greater heat loss and to experience a larger decline in core temperature when subsequently exposed to cold air. The combination of exercise intensity and duration studied in these experiments did not fatigue the shivering response to cold exposure.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Body Temperature Regulation
/
Exercise
/
Cold Temperature
Type of study:
Etiology_studies
Limits:
Adult
/
Humans
/
Male
Language:
En
Journal:
J Appl Physiol (1985)
Journal subject:
FISIOLOGIA
Year:
1999
Document type:
Article
Affiliation country:
Estados Unidos