Association between physical activity (PA) guidelines and body composition variables in middle-aged and older women

The aim of this study was to investigate the association between volume and frequency of moderate-intensity PA and step-based recommendations and individual body composition variables. Our cohort included 167 healthy ambulatory women (mean age 62.8 ± 4.8 years; body mass index [BMI] 27.3 ± 4.2 kg/m2) who carried out daily activities while wearing the ActiGraph GT1M accelerometer over a seven day period. Measurements of BMI, body fat mass index (BFMI), fat-free mass index (FFMI), waist–hip ratio (WHR) and visceral fat area (VFA) were obtained by the InBody 720 multifrequency bioelectrical impedance analysis (MFBIA) device. The significant relationship (rs = 0.66; p < 0.05) was found between moderate PA and steps per day. Moderate PA (r2 = 0.03–0.06) and steps per day (r2 = 0.05–0.20) were significantly associated with observed body composition parameters. Women spending > 300 min/week in moderate PA showed significantly lower values of BFMI (p = 0.02) than those who spent 150–300 min/week. Carrying out moderate PA for 30 min 5 days a week was significantly associated with lower BMI (p = 0.04; η2 = 0.02), BFMI (p = 0.02; η2 = 0.03) and VFA (p = 0.03; η2 = 0.03). In addition, higher amounts of daily steps were significantly associated with lower BMI (p = 0.00; η2 = 0.16), BFMI (p = 0.00; η2 = 0.21), VFA (p = 0.00; η2 = 0.20) and WHR (p = 0.00; η2 = 0.13). A clear association was found between the generally recommended PA guidelines and body composition variables for the women examined in this study. However, the concept of 10,000 steps/day appears to be the strongest predictor of health-related body composition values.