Muscle quality and functionality in older women improve similarly with muscle power training using one or three sets

The present study compared the effects of 12 weeks of muscle power training performing one or three sets on muscle quality assessed by echo intensity (MQ_EI) and index (MQ_index), muscle power-related outcomes, and functional capacity in older women. Participants were randomly assigned into two groups: 1SET (n = 13) and 3SET (n = 13). Lower limb muscle power and vertical jump height were measured during a countermovement jump, maximal rate of torque development (MRTD), and root mean square (RMS) of electromyography signals and rate of rise (RER) of quadriceps maximal electromyography activation during unilateral knee extension at 0-50 and 0-200 ms, MQ_EI, MQ_index (absolute muscle power/MQ_EI, and MRTD/MQ_EI) and functionally in both groups using timed-up-and-go were evaluated before and after training. There were significant and similar (p < 0.05) increases in muscle power, vertical jump height, MQ_EI, MQ_index, and functionally (p ≤ 0.0001) in both groups. In contrast, MRTD increased only in 1SET (p ≤ 0.001), and the RMS_0-200 and RER_0-50 increased for 3SET only (p ≤ 0.05), with no difference between groups (p > 0.05). In conclusion, similar neuromuscular adaptations and improvements in the functional performance occurred in both groups.