The investigation of physical strength/athletic capability in 2009 by the Ministry of Education, Culture, Sport, Science, and Technology suggested that the physical strength levels of children exhibited a tendency to improve, but they were still low compared with those in 1985.

　The purpose of this study was to examine the relationship between physical strength and the percentage of body fat（Fat％), bone mass, dietary and exercise habits in children, and was to investigate their physical traits and life styles which significantly affect their physical strength. We measured body composition, bone mass by supersonic wave method, and physical strength, and also investigated a dietary habit and exercise frequency in 715 elementary school children（male 368, female 347). Physical strength had a significant negative correlation with Fat%, but had a significant positive correlation with bone mass and with exercise duration per week in both genders. A significant negative correlation was found between Fat% and the measurement record of each physical strength, and a significant positive correlation was found between bone mass and the measurement record of each physical strength in both genders respectively. Also a significant positive correlation was found between some measurement records of each physical strength and exercise duration per week in both genders respectively. The data showed that age, body weight and bone mass was a positive factor, while Fat% was a negative factor in related to their physical strength. The girls with higher scores of physical strength have good habits of drinking milk every day and eating break-fast main-dishes, and the higher-score boys have good habits of eating main-dishes in lunch and/or side-dishes for every meal.

　Finally, for the children of high physical strength, it was shown that they have higher lean body mass, longer exercise duration, and well-balanced diet.