Physique indices have been used as convenient measures to assess body composition for school students. However, the measures could not accurately predict the percentage of Body Fat(%BF). This paper proposes a convenient, useful equation to estimate the%BF by using physique indices, physical fitness tests and motor ability tests that heve been widely used in schools. Physique, physical fitness and motor ability were measured for 613 junior high school students, and the%BF was estimated by Bioelectrical Impedance Analysis. Considering practicability, we selected the linear prediction model by which the%BF might be predicted directly without computing the body density. By all combination approach to variable selection, alternative prediction equations are obtained, and the final prediction equation is selected from the viewpoints of accuracy, rationality, stability, cross validity and practicability. Consequently, body mass index(BMI)and 50 m dash are found to be the best predictors, and the following equations are recommended for use in practice: Boy: %BF=0.962×(BMI)+2.52×(50m dash, s)-20.1(R=.745, SEE=2.43%)Girl: %BF=1.76×(BMI)+2.72×(50m dash, s)-31.9(R=.801, SEE=3.50%)where BMI=(body weight, kg)/(height, cm)
2×10
4 %BF can be predicted with a significantly higher accuracy by adding 50 m dash as an additional predictor than by a single predictor, BMI.
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