Moderate exercise increases the post exercise resting warm thermoregulatory response thresholds.
Aviat Space Environ Med
; 71(9): 914-9, 2000 Sep.
Article
em En
| MEDLINE
| ID: mdl-11001344
ABSTRACT
BACKGROUND:
The purpose of this study was to evaluate the effect of exercise on the subsequent post-exercise core temperature thresholds for vasodilation and sweating.METHODS:
On two separate days, with 6 subjects (3 males and 3 females), a whole-body water-perfused suit decreased mean skin temperature until the threshold for vasoconstriction was demonstrated. Mean skin temperature was then slowly increased (approximately 5.0 degrees C x h(-1)) until thresholds for vasodilation and sweating were clearly established. Subjects were cooled by decreasing water temperature until both esophageal and mean skin temperatures returned to near baseline values. Subjects then either performed 15 min of cycle ergometry (60% V(O2max)) followed by 30 min of recovery (Exercise), or remained seated with no exercise for 45 min (Control). Subjects were then cooled again until the onset of cutaneous vasoconstriction followed by a second warming period. The core temperature thresholds for vasodilation and sweating increased significantly by 0.49 degrees C and 0.19 degrees C post-exercise, respectively (p < 0.05). In order to compare thresholds between conditions in which both esophageal and mean skin temperatures were changing, we mathematically compensated for changes in skin temperatures using the established linear cutaneous contribution of skin to the control of vasodilation and sweating (10%).RESULTS:
The calculated core temperature threshold (at a designated skin temperature of 36.0 degrees C) for vasodilation increased significantly from 36.56 +/- 0.12 degrees C to 37.11 +/- 0.21 degrees C post-exercise (p < 0.01). Likewise, the sweating threshold increased from 36.79 +/- 0.18 degrees C to 37.05 +/- 0.23 degrees C postexercise (p < 0.01). In contrast, sequential measurements, without exercise, demonstrate a time-dependent decrease (0.18 degrees C) in the sweating threshold, with no difference in the vasodilation threshold.CONCLUSION:
These data indicate that exercise has a prolonged effect by increasing the post-exercise thresholds for both warm thermoregulatory responses.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Regulação da Temperatura Corporal
/
Exercício Físico
Tipo de estudo:
Clinical_trials
Limite:
Female
/
Humans
/
Male
Idioma:
En
Revista:
Aviat Space Environ Med
Ano de publicação:
2000
Tipo de documento:
Article