Four years old children's physical activity: Can we confirm the difference of physical activity due to the difference of educational program?

We have developed wearable (size: 40×39×8mm, weight: 14g) acceleration and ECG measuring device which can measure physical activity (PA) during awake and sleep behavior continuously 25 hours even for very young children. In order to confirm that the difference of educational program of kindergarten changes children's PA, and to elucidate the other factors which may affect children's PA, we measured 4 y.o. children of a kindergarten twice, on days with educational programs which designed to give children large and normal PA (L and N). In total, on L, children spent significantly more time in moderate-to-vigorous PA and vigorous PA, and significantly less time in sedentary PA than on N. On the other hand, both on L and N, children spend more time in light PA and less time in sedentary PA than previous studies. Comparisons of hourly obtained VPA (vigorous PA) and MVPA (moderate-to-vigorous PA) percentages revealed the effect of specific educational event, importance of playing outside, and largeness of the influence of weather. Heart rates at each PA category suggested that a certain length of continuation of MVPA and VPA is important for the development of cardiorespiratory function of children.