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 (T_re) and skin (T_sk) temperatures were obtained under experimental conditions of resting and bicycling in water.
The rate of decrease in HR and T_re 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.

Cross-sectional growth and developmental data on physique and motor fitness in preschool children aged 3.75 to 6.25 years were obtained at ten year intervals between 1969 and 1999. This study attempted to verify the secular trends in growth and development in preschool children (four- and five-year-old boys and girls) using the wavelet interpolation method (WIM). Height and weight were used for physique, and 20 m dash, standing long jump, and tennis ball throwing for motor fitness. The growth distance and velocity curve for physique and motor fitness of children aged 3.75 to 6.25 years in 1969, 1979, 1989, 1999 were described using the WIM, and the age at local peak velocity (LPV) was derived from the velocity curve. The age at LPV of the physique in boys and girls shifts annually, as does that of motor fitness. Thus, the maturation level was inferred to be early. However, no clear association was shown with age at LPV of physique and motor fitness. A trend was shown for the velocity curve to become more gradual on an annual basis for motor fitness, and a decrease in exercise stimulation of the body was inferred to reflect individual biological variation.

In 31 asthmatic children, we investigated the change of the structure on the time of living, an amount of exercise by pedmeter and measured pulmonary ventilatory function during 28 weeks swimming training.
The result showed 58.07% of contribution factor to the structure on the time of living on children with asthma and dynamic play time after school were significantly shorter in asthmatic than non-asthmatic children (p<0.05) . After 28 weeks, we could not find any significantly differences of dynamic play time between asthmatic and nonasthmatic children.
An amount of exercise in daily life from the point of view of walking step number by pedmeter were significantly less in aged 6-9 years boys and girls, and aged 10-12 years boys than non-asthmatic children (respectively, p<0.05, p<0.01) . However, after 28 weeks, we could not find any differences between asthmatic and non-asthmatic children.
Forced vital capacity (FVC) and rate of forced expiratory volume on one second (% FEV_1.0) were increased after 28 weeks than the begining of swimming, and we found the strength of their breathing muscles.
On according to perform the great swimming distances (averages 220m in boys, 325m in girls), all asthmatic children became very lively and actively.