The importance of maintaining muscle strength and muscle function as we age is often overlooked. To a large degree the quality of your life is directly related to your ability to physically move – the quality of your muscle function. That’s why it’s vital that you take steps to maintain and improve your muscle function. The loss of muscle mass associated with aging is called sarcopenia. But, age-related muscle loss is not cast in stone. It can be prevented. And, it looks like hormone replacement therapy is one way to enhance muscle function based on this study from The Journal of Physiology. This is especially good news for women who have less muscle mass to begin with, and therefore less reserve. Injuries from falling affect women more often than men and many fall are related to lack of balance and muscle strength.
This study involved only post menopausal women. It is unique because the effects of genetics were eliminated by studying identical twins in which only one of each pair received hormone replacement therapy (HRT) while the other twin served as a control. This study was also the first to look at the effects of HRT at the cellular and molecular levels.
The study showed that with HRT muscle strength increased because individual muscle fibers became stronger without any change in muscle size. The study researchers postulated that HRT positively alters the contractile proteins of muscle offsetting some of the effects of aging. Biopsies of the HRT treated muscles also showed better organization of the myonuclei which regulate cellular protein transport.
The study did not look at the possible additional benefits of weight or resistance training coupled with HRT might have on muscle function in women compared to HRT alone. But, studies performed in men have shown greater strength improvement when resistance training is added to testosterone replacement compared to testosterone replacement alone. I suspect that the combination of HRT and strength training in women would yield similar findings.