Last updated: 3 August 2026
Reviewed by Jordan Makin, FA Level 2 Football Coach
Muscle hypertrophy is the enlargement of muscle fibres in response to mechanical tension, metabolic stress and muscle damage from resistance training. Two types are distinguished: myofibrillar hypertrophy (growth of the contractile proteins actin and myosin, increasing strength and size) and sarcoplasmic hypertrophy (growth of the energy-storing components, increasing muscle volume more than strength). Research consensus for optimal hypertrophy: 6-20 rep ranges, 10-20 sets per muscle per week, training to near-failure, adequate protein (1.6-2.2 g/kg/day) and caloric surplus or maintenance.
Key points
- Muscle fibre enlargement from resistance training
- Requires mechanical tension + adequate recovery
- 6-20 rep ranges, 10-20 sets/muscle/week
- 1.6-2.2g protein/kg/day + caloric surplus