Similar Effects of 24 Weeks of Resistance Training Performed with Different Frequencies on Muscle Strength, Muscle Mass, and Muscle Quality in Older Women

The purpose of this study was to analyze the effects of 24 weeks of resistance training (RT) performed 2 vs. 3 times per week on muscle strength, muscle mass, and muscle quality in older women. Thirty-nine older women (≥ 60 years old) were randomly assigned to two groups according to RT frequency (G2× = two sessions per week, n=19; and G3× = three sessions per week, n=20) and were submitted to 24 weeks of whole-body RT, divided into two stages of 12 weeks. In the first stage, participants performed 1 set of 10 to 15 repetitions in each of eight exercise, whereas in the second stage, they performed 2 sets of 10 to 15 repetitions. Muscle strength was assessed by one repetition maximum (1RM) tests in chest press, knee extension, and biceps preacher curl, while the lean soft tissue was estimated by DXA. The muscle quality index was determined by the ratio between strength and lean soft tissue. There were observed similar increases between groups for muscle strength (G2x=19.5%; G3×=22.2%), lean soft tissue (G2x=3.0%; G3×=1.6%), and muscle quality index (G2x=16.0%; G3×=21.1%). These results indicate that RT-induced muscular adaptation occurs regardless of training twice or thrice a week in older women. Instructors, coaches and practitioners can choose their training frequency preference, since both frequencies provided similar adaptations.