Oestrogen plays an underappreciated role in skeletal muscle physiology. Oestrogen receptors are present in skeletal muscle fibres and satellite cells, the muscle stem cells responsible for repair and growth. Oestrogen promotes muscle protein synthesis, reduces muscle protein breakdown, and supports satellite cell proliferation. At the menopause, its decline contributes to an acceleration of the age-related sarcopenia that begins in the mid-30s. The average postmenopausal woman who does not undertake deliberate resistance training loses muscle at a rate of 1 to 2 percent per year alongside an increase in intramuscular fat deposition that is not reflected in total body weight.
Body Composition Without the Scale
A common and distressing pattern in perimenopause is weight stability on the scales accompanied by significant deterioration in body composition: clothes fit differently, muscle definition decreases, and body fat redistributes toward the abdomen. This occurs because oestrogen normally promotes peripheral fat deposition, and its decline shifts fat storage centrally. Central adiposity is metabolically active, producing oestrone and inflammatory cytokines, and is a stronger risk factor for cardiovascular disease and metabolic syndrome than total body fat.
Resistance Training as the Primary Intervention
Progressive resistance training is the most effective intervention for reversing menopausal body composition changes. A randomised controlled trial by Villareal et al. demonstrated that resistance training in postmenopausal women over 12 months produced significant increases in lean mass, decreases in fat mass, and improvements in strength and metabolic markers. The response to resistance training is preserved in postmenopausal women, though it may require higher volume and progressive overload compared to premenopausal women, and adequate protein intake is critical to support the training stimulus.
Protein Requirements in Menopause
The combination of anabolic resistance from oestrogen decline and the naturally increasing anabolic resistance of ageing means that postmenopausal women require substantially more protein per kilogram of body weight than guidelines written for younger women suggest. The current evidence supports 1.6 to 2g of protein per kilogram of body weight per day for postmenopausal women who are undertaking resistance training. Distributing this across three to four meals of 30 to 40g each is more effective for muscle protein synthesis than the same total consumed unevenly.
- Undertake progressive resistance training three times per week targeting all major muscle groups
- Eat 30 to 40g of high-quality protein per meal, totalling 1.6 to 2g per kilogram of body weight daily
- Do not reduce caloric intake aggressively alongside training: muscle requires a sufficient energy substrate
- Consider HRT in the context of body composition: oestrogen preserves muscle satellite cell function and enhances the response to training
- Track body composition with DEXA or tape measurements rather than scale weight alone
Sources
- Greising, S.M., et al. (2009). Hormone therapy and skeletal muscle strength: a meta-analysis. Journals of Gerontology: Biological Sciences, 64(10), 1071-1081.
- Sipila, S., et al. (2001). Effect of strength and endurance training on isometric muscle strength and walking speed in elderly women. Acta Physiologica Scandinavica, 156(4), 457-464.