Muscle strength in obese elderly women: effect of recreational physical activity in a cross-sectional study

Background: Muscle strength (MS) may be impaired in obese persons, and this impairment may be a consequence of both obesity and low physical fitness. Objective: We investigated whether MS differed between obese [body mass index (BMI; in kg/m 2 ) > 29], normal-weight (BMI = 24-29), and lean (BMI 0.05). When adjusted for age, height, RPA, pain, depression, and appendicular skeletal muscle mass, MS did not differ significantly between obese, normal-weight, and lean subjects, except for knee extension (significant interaction effect with RPA; P = 0.01). With increasing BMI, lower limb strength did not change in the sedentary women but increased in active (≥ I h/wk in ≥ 1 RPA for ≥ 1 mo) women. All adjusted MS measures in active participants were significantly higher (P < 0.001) than those in their sedentary peers. Conclusion: The adjusted MS of elderly women is not associated with obesity but is higher in active subjects than in sedentary ones, especially in the lower limbs of obese subjects.