A CROSS-SECTIONAL STUDY ON BODY-COMPOSITION AND ENERGY-EXPENDITURE INWOMEN ATHLETES DURING AGING

The relationships between total and regional body composition, intra-a bdominal adipose tissue (IAAT), resting metabolic rate (RMR), and subs trate oxidation were examined in 43 highly trained women athletes and 14 sedentary women aged 18-69 yr. Athletes were divided into four grou ps (18-29, 30-39, 40-49, and 50-69 yr) and controls into two groups !1 8-29 and 40-50 yr). Maximal oxygen consumption declined with age (r = -0.52, P < 0.0005) in the athletes and was higher in all groups of ath letes than in controls (P < 0.0001). No differences in percent fat and fat-free mass (FFM) were found between the youngest and oldest athlet es. Although body mass index was <25 kg/m(2) in all subjects, percent body fat and total fat mass were higher in controls than in athletes f or both young and older women (all P < 0.05). FFM was higher in young athletes than in young controls (P < 0.0001). Despite similar percent fat among athletes, IAAT increased with age (r = 0.75, P < 0.0001), bu t subcutaneous abdominal fat and sagittal diameter did not. IAAT and s ubcutaneous abdominal fat were also higher in young controls than in y oung athletes and in older controls than in older athletes !all P < 0. 005). Age and FFM were independent predictors of the decline in RMR in the athletes. Fat oxidation (g/day) was highest in the youngest athle tes and declined with age (r = -0.47, P < 0.005). We conclude that int ense chronic exercise in women athletes prevented the decline in FFM w ith age. Endurance-trained women have low IAAT stores. which may poten tially reduce subsequent risk associated with the metabolic syndrome.