This investigation examined alterations in neuromuscular drive for dynamic and static muscle contractions, muscle strength, and cross-sectional area (CSA) with a 12-week progressive resistance-training program (PRT). Nine healthy men (70.0 ± 1.7 years) were evaluated for maximal and submaximal neuromuscular drive (integrated electromyography [IEMG]), whole-muscle strength, isokinetic power, and thigh CSA. The results demonstrated no significant differences pre- to post-PRT in the submaximal IEMG signals (p > .05). IEMG increased (p < .05) for the maximal static contraction (29% ± 12%) and isokinetic velocities concentrically and eccentrically. There was an increase (p < .05) in maximal static strength (27% ± 5%), isokinetic concentric and eccentric strength, muscle power, IRM (47% ± 6%), and CSA (6% ± 1%; p < .05). The results reveal significant neuromuscular-drive alterations in concentric and eccentric dynamic contractions with PRT in older men and indicate that their neuromuscular drive contributes significantly to improving their concentric and eccentric skeletal-muscle strength.
The authors are with the Human Performance Laboratory. Ball State University, Muncie, IN 47306.