Functional capacity depends on lower limb muscle strength rather than on abdominal obesity in active postmenopausal women.

Objective: An association has been found between abdominal obesity and functional capacity (FC) in the literature where waist circumference has been used to infer abdominal obesity. However, most studies focused on evaluating predictors of FC and functional disabilities only in sedentary people. This study aimed to examine whether abdominal obesity is associated with FC in physically active postmenopausal women.

Methods: Forty-four active (>7,500 steps/d) postmenopausal women were recruited. Body composition and distribution (DXA), FC (chair-stand/alternate-step/one-leg-stance), handgrip strength and knee extensor strength (dynamometry), steps/d (accelerometer), and cardiorespiratory function (spirometry/VO2max) were measured. The cohort was divided into groups based on a FC score (1-4 scale using quartiles). Pearson's correlation, t test, and linear regression were applied using SPSS (17.0).

Results: There was no correlation for body composition or BMI with FC score. However, waist circumference (r = -0.34, P = 0.024), handgrip (r = 0.32, P = 0.036), knee extensor strength (r = 0.43, P = 0.003), and VO2max (r = 0.41, P = 0.006) were significantly correlated with FC score. In addition, when the highest quartile group was compared with the lowest one, a significant difference was observed for knee extensor strength (P = 0.003), which was also the only variable inserted into the FC prediction equation derived from the stepwise regression model (r = 0.19, F = 9.582, P = 0.003).

Conclusions: Our results demonstrate an association between abdominal obesity and FC in active postmenopausal women and that the strongest association and the best predictor of FC was lower limb muscle strength. Thus, active postmenopausal women with abdominal obesity may not necessarily have a reduced FC if lower limb muscle strength is preserved.