Purpose: To compare the effects of three water-based resistance trainings on neuromuscular parameters of older women.
Method: Thirty-six women were randomized to groups: simple set of 30 seconds (1 × 30 s, 66.41 ± 4.71 years, n = 12), multiple sets of 10 seconds (3 × 10 s, 66.50 ± 4.74 years, n = 11), and simple set of 10 seconds (1 × 10 s, 65.23 ± 3.93 years, n = 13). Maximal isometric strength concomitantly with neuromuscular activity during extension and flexion knee was evaluated. In the same exercises, rate of force development at different time intervals was measured. Finally, functional capacity was assessed.
Results: All trainings promoted similar improvements in the rate of force develpment of extension (effect size RFD 50 ms: 1 × 30 s .49, 3 × 10 s .67, 1 × 10 s .65; ES RFD 100 ms: 1 × 30 s .76, 3 × 10 s .80, 1 × 10 s .63; ES RFD 250 ms: 1 × 30 s .31, 3 × 10 s .49, 1 × 10 s .37) and flexion knee (ES RFD 50 ms: 1 × 30 s .59, 3 × 10 s .31, 1 × 10 s .48; ES RFD 100 ms: 1 × 30 s .41, 3 × 10 s .44, 1 × 10 s .42; ES RFD 250 ms: 1 × 30 s .57, 3 × 10 s .36, 1 × 10 s .43; ES RFD maximal: 1 × 30 s .63, 3 × 10 s .23, 1 × 10 s .26), however only the 3 × 10 s group improved the performance in the 8-foot up-and-go test (ES 3 × 10 s: .93, 1 × 30: .39, 1 × 10 s: .23). There was a maintenance of the isometric force and neuromuscular activity, except for the activity of the rectus femoris that showed an increase after training in all groups (ES 3 × 10 s: .04, 1 × 30: .36, 1 × 10 s: .50).
Conclusion: Water-based resistance training using simple or multiple sets promotes the same gains in rapid strength, however only multiple sets induced improvement on functional capacity.
Keywords: Exercise; aging; electromyography; rate of force development.