- Satellite cell activation and fusion accompany resistance exercise training.
- Aerobic exercise training is capable of inducing subtle muscle fibre hypertrophy; however, the role of satellite cell activation during aerobic exercise-induced muscle adaptation is unknown.
- Twelve weeks of aerobic training in sedentary subjects yielded an increase in myosin heavy chain type I and type II muscle fibre cross-sectional area.
- Satellite cell activation and myonuclear addition occurred only in myosin heavy chain type I fibres, with no change in myosin heavy chain type II fibres.
- These results help us better understand the role of satellite cells in muscle fibre adaptation to aerobic exercise, and suggest differential fibre type regulation of the myonuclear domain.