Fig. 1. Longitudinal changes (mean 8-yr) in fat-free mass (FFM) (black bars) and body fat (BF) (gray bars) in sedentary (S) and active (A) men and women aged <45 and 45 y. Differences were significant for FFM in sedentary versus active women <45 yr (p = 0.02); active men vs active women <45 yr (p = 0.007); and <45 yr vs 45 yr active men (p = 0.02) and sedentary women (p = 0.01; and for BF in sedentary vs active men 45 yr. The ANOVA for FFM, which included sex, age and activity, was significant only for age (<45 versus 45 yr: p < 0.001). There was no interaction between the main effects. The ANOVA for BF was significant only for the interaction between sex and activity (p 0.02). The ANOVA for weight was significantly for age (<45 versus 45 yr: p 0.03) and sex (p 0.02). There was no interaction between the main effects.