Last updated: 4 October 2026
Reviewed by Jordan Morley, 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.
- 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
In practice
Muscle hypertrophy occurs when resistance training creates mechanical tension and metabolic stress that trigger muscle protein synthesis to exceed breakdown over time — research shows a wide range of rep ranges (roughly 6-30 reps per set) can all drive meaningful hypertrophy as long as sets are taken close to failure, which has shifted hypertrophy programming away from rigid rep-range dogma toward more flexible approaches.
FAQ
What rep range is best for muscle growth?
Research shows hypertrophy can occur across a wide range (roughly 6-30 reps per set) provided sets are taken close to failure, so total volume and proximity to failure matter more than a single 'ideal' rep range.
Is more training volume always better for hypertrophy?
No — more volume helps up to a point, but beyond an individual's recovery capacity, additional volume stops producing extra growth and can instead increase fatigue and injury risk without added benefit.