Plasma hormones, muscle mass and strength in resistance-trained postmenopausal women

To associate changes of body composition, muscle strength (MS) and plasma hormones (PH) in resistance-training protocol in sedentary postmenopausal women (PMW).

This randomized controlled trial, Brazilian 43 PMW (45-70-year-old) able for physical exercises were selected after they have accomplished medical and ethical criteria. They were assigned in two groups: RT, resistance training (n=22); and CT, not trained control (n=21); with supervision sessions of two to three exercise for large and one exercise for smaller groups in three series of 8-12 rep. (60-80%1RM) for each exercise. The training period lasted 16 weeks and was preceded by low-load exercise (40-50%1RM) adaptation period of 4 weeks (3/(times week)). Body weight, height, body mass index (BMI), and composition (BIA) along with fast-PH (FSH, LH, estradiol, cortisol, IGF-1 and testosterone) were assessed before (M0) and after (M16) the 4 weeks period with the MS (1RM) determined also at 8 weeks (M8). The values were correlated by Person's test and the means compared by Student's t-test and ANOVA.

At baseline both groups were similar in age, time of PMW, body composition, MS and fast-PH. However after 16 weeks, RT presented higher BMI (2.1%), IGF-1 (37.8%) and MM gain (1.8+/-0.8 kg) than CT. MM correlated positively with IGF-1 (r=0.45, p<0.05) and MS progressively increased in all exercise greater in pectoral than legs and upper arms.

Former sedentary postmenopausal women submitted to resistance training gained MM and MS irrespectively of fat mass changes but significantly associated with IGF-1 increase.