Purpose – justified the use of physical activity for children as a criterion for recreation. Studied the relationship of this index with morphological and functional features of development and the level of hygiene knowledge. The study involved 54 pupils aged 10-14 years. Results: It is shown that the level of physical activity (1282,37 ± 289,20) locomotion per day. The value of basal metabolism reaches (1350,51 ± 33,69) kcal. Established direct correlation with the main motor activity exchange (r = 0,81); body weight (r = 0,80); circumference of the chest in the pause / inspiratory / expiratory (r = 0,70-0,71); vital capacity (r = 0,37); hand muscular strength (r = 0,51-0,58). The estimation of the physical development of children by Quetelet index: mass deficit is set at 12.96%, 29.63% obese, normal physical development at 51.85% overweight at 5.56%. Conclusions: The recommended value of physical activity as a criterion for recreation and health of school children. Its definition reflects the functional state of the school, as one of the criteria for defining the health, predicts its changes, which is especially valuable in monitoring.