Muscle growth occurs whenever the rate of muscle protein synthesis is greater than the rate of muscle protein breakdown. The process is based on the following sequence:
- Stress: Lifting weights or performing resistance exercises.
Resistance exercise can profoundly stimulate muscle cell growth (or hypertrophy) which results in strength increases.
- Damage: Creating microscopic tears in muscle fibers.
These tears are a natural part of the muscle building process and stimulate the growth response.
- Repair: Using nutrients and hormones to rebuild and strengthen the muscle.
During rest and recovery, the body repairs the damaged muscle fibres. A hormone response and nutrients (adequate protein intake, along with sufficient carbohydrates and healthy fats), are crucial for providing the building blocks and energy for muscle repair and growth. Rest allows the body to repair muscle tissue and synthesise the new proteins needed for growth.
- Growth: Increasing the size and strength of the muscles.
Muscle growth is limited by the number of muscle fibres, so the body can only increase the size of existing fibres, we can’t create new ones. Increasing the size of your muscle fibres takes time and effort, it’s estimated to take around 12 weeks, depending on a number of factors. However, you may see and feel gains well before that; our neuromuscular systems adapt rapidly in response to repeated, challenging new movements. Our movement patterns and our response to load quickly become much more efficient. So we might be able to increase the weights before we have actual muscle changes – those will follow.
We lose muscle mass as we get older and this loss is referred to as sarcopenia. Happily, the detrimental effects of aging on muscle have been shown to be lessened or even reversed with regular resistance exercise.
Very recent research shows that women in midlife can gain muscle whether they are pre, peri or post-menopausal. This 2025 study compared the effects of a 12-week bodyweight and resistance band programme, done four times per week, on women at different stages of menopause.
Results at the end of the 12-week programme included:
Hip strength: ⬆️19-20%
Dynamic balance: ⬆️10%
Muscle thickness: ⬆️12%
Gains were similar across the board for women pre-, peri-, and post-menopause, so we shouldn’t be put off by the narrative that age makes it harder to get stronger; exercise can help — no matter where you are in the menopause transition. It’s also heartening to see that gains were made at relatively low load (with bodyweight & band exercises) when the dominant narrative is that perimenopausal women must ‘lift heavy sh*t’.
And importantly, even light resistance exercise ALSO improves the connective tissue quality, joint mobility, balance, mood, circulation, cognition ….I could go on!
Refs
SCHOENFELD, BRAD J. The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training. Journal of Strength and Conditioning Research 24(10):p 2857-2872, October 2010. | DOI: 10.1519/JSC.0b013e3181e840f3
SVENSEN, ERIKA; KOSCIEN, CHRISTOPHER P.; ALAMDARI, NIMA; WALL, BENJAMIN T.; STEPHENS, FRANCIS B.. A Novel Low-Impact Resistance Exercise Program Increases Strength and Balance in Females Irrespective of Menopause Status. Medicine & Science in Sports & Exercise 57(3):p 501-513, March 2025. | DOI: 10.1249/MSS.0000000000003586