Related Experiment Videos
Compensatory muscle fiber hypertrophy in elderly men
A Aniansson1, G Grimby, M Hedberg
1Department of Rehabilitation Medicine, University of Göteborg, Sahlgren Hospital, Sweden.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|September 1, 1992
Summary
Elderly men experienced muscle strength decline and loss of body cell mass over 11 years. However, maintained physical activity led to muscle fiber hypertrophy and maintained oxidative capacity between ages 76-80.
Area of Science:
- Gerontology
- Exercise Physiology
- Skeletal Muscle Biology
Background:
- Aging is associated with progressive muscle loss and strength decline.
- Understanding the long-term adaptations in elderly individuals is crucial for maintaining function.
Purpose of the Study:
- To longitudinally assess changes in muscle strength, morphology, and enzymatic activity in elderly men over 11 years.
- To investigate the impact of maintained physical activity on age-related muscle changes.
Main Methods:
- Longitudinal study of nine elderly men over 11 years, with measurements at three time points.
- Assessed muscle strength via isometric and isokinetic knee extension.
- Analyzed vastus lateralis muscle biopsy for fiber type composition, fiber area, and enzymatic activity.
Main Results:
- Body cell mass decreased by 6%; knee extension strength declined by 25-35%.
- Significant reduction in type IIb fibers and increase in type I and II fiber areas observed between ages 76-80.
- Enzymatic activities of myokinase and lactate dehydrogenase decreased, while oxidative enzyme activities remained stable.
Conclusions:
- Muscle fiber hypertrophy in active elderly men (76-80 yr) may compensate for motor unit loss.
- Maintained physical activity appears to preserve oxidative capacity in aging skeletal muscle.