Physical fitness improvement in overweight postmenopausal women who do not lose fat mass in response to exercise training

OBJECTIVE: The aim of this study was to examine if overweight postmenopausal women who do not experience fat mass loss after a 1-year aerobic exercise (AE) and resistance training (RT) program can still improve physical fitness. METHODS: Thirty-one overweight women (body mass index 28-40 kg/m or waist circumference ≥88 cm) participated in three weekly supervised AE and RT sessions for 1 year. All women were categorized according to their fat mass changes after the intervention: 14 women were considered as responders (fat mass loss ≥5% of initial fat mass) and 17 as nonresponders (fat mass loss <5% of initial fat mass). The main outcome measures were absolute and relative body strength, peak aerobic capacity, lower limbs power, flexibility, and body composition (DXA). Total energy intake (3-day dietary record) and physical activity level (physical activity scale for the elderly questionnaire) were also measured before, halfway through and after the intervention. RESULTS: At baseline, nonresponders participants had higher body mass index (P = 0.04). After the intervention, relative and absolute upper and lower body strength, peak aerobic capacity (all P < 0.005), and flexibility increased similarly in the nonresponders and responders groups (P = 0.01). CONCLUSIONS: Although some participants did not respond to exercise by decreasing fat mass, they still experienced important physical fitness benefits from AE and RT. These results suggest that body composition changes should not be the sole indicator of the benefits of exercise in overweight postmenopausal women.