<p>Maximal weight-lifting performance, isometric strength, isokinetiic torque, whole muscle and individual fibre cross-sectional areas, and muscle evoked contractile properties were assessed in 14 elderly males before and after 12 weeks of weight-lifting training. Dynamic elbow flexion training of one arm resulted in a significant 48% mean increase in the maximal load that could be lifted once (1 RM) and a smaller improvement in isokinetic torque (8. 8%) but no change in isometric strength. In the contralateral control arm, 1 RM and isokinetic torque increased by 12.7 and 6. 5 %, respectively, but isometric strength did not change. The interpolated twitch technique confirmed complete motor unit activation during a maximal isometric contraction of the elbow flexors before and after training. Bilateral leg press training effected mean increases of 17 and 23% in isokinetic torque and dynamic lifting capacity, respectively. The mean maximal cross-sectional area of the elbow flexors (biceps brachii and brachialis) increased by 17.4% in the trained arm but did not change in the control arm. The increase in the mean area of the Type II fibres in the biceps brachii muscle in the trained arm (30.2%) was greater than the corresponding change in the control arm (10.7%, P< 0.05). The most significant change in the the evoked contractile properties of the trained elbow flexors was the increase in twitch half-relaxation time. It is concluded that older individuals retain the potential for significant increases in strength performance and upper limb muscle hypertrophy in response to overload training.</p> / Master of Science (MS)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/11895 |
| Date | 04 1900 |
| Creators | Brown, Allan |
| Contributors | McCartney, Neil, Human Biodynamics |
| Source Sets | McMaster University |
| Detected Language | English |
| Type | thesis |
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