Abstract

Objective: To examine the effects of 12 weeks of high-speed resistance training (RT) versus low-speed RT on muscle strength [one repetition of maximum leg-press (1RM(LP)) and bench-press (1RM(BP)), plus dominant (HGd) and non-dominant maximum isometric handgrip], power [counter-movement jump (CMJ), ball throwing (BT) and 10-m walking sprint (S10)], functional performance [8-foot up-and-go test (UG) and sit-to-stand test (STS)], and perceived quality of life in older women. Methods: 45 older women were divided into a high-speed RT group [EG, n = 15, age = 66.3 +/- 3.7 y], a low-speed RT group [SG, n = 15, age = 68.7 +/- 6.4 y] and a control group [CG, n = 15, age = 66.7 +/- 4.9 y]. The SG and EG were submitted to a similar 12-week RT program [3 sets of 8 reps at 40-75% of the one-repetition maximum (1 < RM), CMJ and BT] using slow, controlled (3 s) concentric muscle actions for the SG and using fast, explosive (<1 s) concentric muscle actions for the EG (20% less work per exercise without CMJ and BT). Results: Over the 12-week training period, both RT groups showed small to large clinically significant improvements in the dependent variables; however, a significant difference was found between the EG and SG for the performance changes in BT, S10 and UG (20% vs. 11%, p < 0.05; 14% vs. 9%, p < 0.05; 18% vs. 10%, p < 0.01; respectively). No significant changes were observed for the CG. Conclusion: Both RT interventions are effective in improving functional capacity, muscle performance and quality of life in older women, although a high-speed RT program induces greater improvements in muscle power and functional capacity. (C) 2014 Elsevier Inc. All rights reserved.