Abstract
The metabolic rate, HR and thermal responses of 26 children, aged 7-8 years (6 boys, 7 girls) and aged 9-11 years (7 boys, 6 girls), were measured during head-out immersion in water. In the water bath, a bicycle ergometer was set and water temperature wes maintained at 26±1°C. Thirty minutes measurements of heat production (cal⋅min-1⋅m-2), HR, rectal (Tre) and skin (Tsk) temperatures were obtained under experimental conditions of resting and bicycling in water.
The rate of decrease in HR and Tre were significantly greater in the younger group than the older, irrespective of sex, in resting condition (P<0.001, P<0.01, respectively), but any differences could not be found in bicycling condition.
Heat conductanc (K) from body surface were calculated. In resting condition in water, older girl group showed K=94.1 (cal⋅m2⋅°C ⋅min-1) and younger boy group K=142.2 and in bicycling condition in water they were 213.8 and 276.9, respectively.
