Effects of Different Resistance Training Loads on the Muscle Quality Index in Older Women

Ribeiro, AS, Picoloto, A, Nunes, JP, Bezerra, ES, Schoenfeld, BJ, and Cyrino, ES. Effects of different resistance training loads on the muscle quality index in older women. J Strength Cond Res 36(5): 1445-1449, 2022-The purpose of this study was to investigate the effects of resistance training (RT) performed using low vs. moderate loads on muscular strength, muscle mass, and muscle quality index (MQI) in older women. Twenty-seven older women (71.5 +/- 5 years, 65.2 +/- 11 kg, 154.2 +/- 5 cm, and 27.4 +/- 4 kg center dot m(-2)) were randomized into 2 groups: one that performed RT with a low load (LOW, n = 13) and another that performed RT with a moderate load (MOD, n = 14). An 8-week RT program was performed 3 d center dot wk(-1). Outcomes included 1-repetition maximum (1RM) tests and assessment of body composition by dual-energy X-ray absorptiometry. The LOW load consisted of a relative load at 15RM, whereas the MOD load consisted of a relative load at 10RM. Both groups presented significant changes from pre-training to post-training for chest press 1RM (LOW = 10.3%, and MOD = 11.1%), knee extension 1RM (LOW = 14.4%, and MOD = 16.6%), preacher curl 1RM (LOW = 12.4%, and MOD = 12.0%), fat-free mass (LOW = 2.1%, and MOD = 1.9%), body fat (LOW = -3.2%, and MOD = -2.7%), and MQI (LOW = 10.6%, and MOD = 11.3%). Results were similar (p > 0.05) between groups. These findings suggest that LOW and MOD loads are equally effective for promoting improvements in muscular strength and muscle growth as well as the MQI in older women.