EFFECTS OF 24 WEEKS OF PROGRESSIVE RESISTANCE TRAINING ON KNEE EXTENSORS PEAK TORQUE AND FAT-FREE MASS IN OLDER WOMEN

Rabelo, HT, Bezerra, LA, Terra, DF, Lima, RM, Silva, MAF, Leite, TK, and de Oliveira, RJ. Effects of 24 weeks of progressive resistance training on knee extensors peak torque and fat-free mass in older women. J Strength Cond Res 25(8): 2298-2303, 2011-This study examined the effects of resistance training (RT) on knee extensor peak torque (KEPT) and fat-free mass (FFM) in older women. Seventy-eight volunteers (67.1 +/- 5.9 years old) underwent 24 weeks of progressive RT (RTG) while 76 (67.4 +/- 5.9 years old) were studied as controls (CG). Dominant knee extension peak torque was assessed using an isokinetic dynamometer (Biodex System 3) and FFM measurements were performed by dual-energy x-ray absorptiometry. Muscle strength and FFM were evaluated before and after the intervention in all volunteers. Participants in the RTG trained major muscle groups 3 times per week during 24 weeks. Training load was kept at 60% of 1 repetition maximum in the first 4 weeks, 70% in the following 4 weeks, and 80% in the remaining 16 weeks, with repetitions, respectively, decreasing from 12, 10, and 8. A Split-plot analysis of variance was performed to examine between-and within-group differences, and the level of significance was accepted at p <= 0.05. It was observed that the RTG showed significant increases in KEPT (from 89.9 +/- 21.8 to 102.8 +/- 22.6 N.m; p < 0.05) and FFM (from 36.4 +/- 4.0 to 37.1 +/- 4.2 kg, p < 0.05). Appendicular FFM was also significantly increased after the intervention period in the RTG (13.9 +/- 1.8 to 14.2 +/- 1.9 kg, p < 0.05). None of these changes were observed for the CG. Consistent with the literature, it is concluded that a progressive RT program promotes not only increases in muscle strength, as evaluated by an isokinetic dynamometer, but also in FFM as evaluated by the DXA, in elderly women.