Leisure time physical activity is a significant predictor of body density in men

The purposes were to: (a) develop and cross-validate a prediction equation for body density with leisure time physical activity (LTA) serving as a potential predictor, and (b) determine whether the addition of LTA to previously published regression equations would improve their prediction. Body density (hydrostatic weighing) was measured in a validation group of 193 men (18-78 years), and was predicted by age, body mass index, subscapular skinfold, abdominal skinfold, thigh skinfold, waist circumference, and LTA. This equation cross-validated on an independent group of men (N = 96). Consequently, groups were combined (N = 289) to yield a new equation that also included the same seven variables plus the waist/thigh circumference ratio (R = 0.90, R² = 0.81, SEE = 0.0085 g/ml, p < 0.0001). Additionally, LTA improved the prediction of published equations obtained from men of various ages. In conclusion, LTA is an independent predictor of body density in healthy men comprising a wide age range.