Abstract
Background Adequate muscle fibre perfusion is critical for the maintenance of muscle mass; it is essential in the rapid delivery of oxygen, nutrients and growth factors to the muscle, stimulating muscle fibre growth. Muscle fibre capillarization is known to decrease substantially with advancing age. However, whether (relative) low muscle fibre capillarization negatively impacts the muscle hypertrophic response following resistance exercise training in older adults is unknown.
Methods Twenty-two healthy older men (711years) performed 24weeks of progressive resistance type exercise training. To assess the change in muscle fibre characteristics, percutaneous biopsies from the vastus lateralis muscle were taken before and following 12 and 24weeks of the intervention programme. A comparison was made between participants who had a relatively low type II muscle fibre capillary-to-fibre perimeter exchange index (CFPE; LOW group) and high type II muscle fibre CFPE (HIGH group) at baseline. Type I and type II muscle fibre size, satellite cell, capillary content and distance between satellite cells to the nearest capillary were determined by immunohistochemistry.
Results Overall, type II muscle fibre size (from 5150 +/- 234 to 6719 +/- 446 mu m(2), P
Conclusions Type II muscle fibre capillarization at baseline may be a critical factor for allowing muscle fibre hypertrophy to occur during prolonged resistance exercise training in older men.
Original language | English |
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Pages (from-to) | 267-276 |
Number of pages | 10 |
Journal | Journal of cachexia, sarcopenia and muscle |
Volume | 8 |
Issue number | 2 |
DOIs | |
Publication status | Published - Apr 2017 |
Keywords
- Capillary
- Exercise training
- Elderly
- Fibre growth
- Skeletal muscle
- LIMB BLOOD-FLOW
- STEM-CELL DYSFUNCTION
- HUMAN SKELETAL-MUSCLE
- AGE-RELATED DECREASES
- SATELLITE CELL
- PROTEIN SUPPLEMENTATION
- VASCULAR CONDUCTANCE
- PHYSICAL-DISABILITY
- HEALTHY HUMANS
- ELDERLY-MEN