What Happens To Our Muscles As We Age?

The Centers for Disease Control and Prevention recommends adults over 65 devote at least two days a week to strength training. That's because our muscles lose both size and strength over the years, according to Better Health. The muscle fibers themselves get smaller and we have less of them. It takes longer for us to replace muscle tissue, and it's often replaced with tougher tissue. Our nervous system also changes with age, which means that we lose muscle tone and the muscles themselves can't contract as well. This can put us in a vicious cycle where our muscles get weak, we're too tired to exercise, then we don't want to exercise (via Healthline).

According to Cleveland Clinic, we begin losing muscle mass in our 30s, but muscle loss accelerates after the age of 65. In fact, this age-related decline in muscle mass is more pronounced in men, according to a 2014 article in Sports Health.

We need to keep muscle as we age to limit the risk of sarcopenia, which is the medical term for this age-related muscle decline, according to Cleveland Clinic. Sarcopenia is the main contributor to older adults falling and losing their quality of life. It prevents seniors from performing daily activities and living comfortably on their own. People who have sarcopenia have poor balance, walk slowly, and have problems climbing stairs.

Not only does sarcopenia reduce the quality of life, but it also reduces life span (via Healthline). Much of the muscle decline in older adults comes from reduced physical activity, less protein in the diet, inflammation from injury or illness, or stress from chronic diseases. As we age, we also have lower levels of hormones that maintain muscle mass and bone, such as testosterone and estrogen (via 2014 article in Sports Health). The good news is that we can make changes to slow and even reverse this muscle decline, according to Better Health.

Even if someone is already experiencing muscle loss, muscles can still respond well to strength training, according to a 2014 article in Sports Health. Adults up to 90 years old have even improved their strength. A 2022 review in Frontiers in Sports and Active Living found that strength training is best to combat sarcopenia. The researchers recommended methods like suspension training to activate core muscles. They also suggested low weights with low reps and short breaks for seniors. 

Because poor nutrition can contribute to age-related muscle decline, Cleveland Clinic suggests adding 20 to 35 grams of protein to each meal to maintain muscle mass. However, the 2014 article said more research was needed on how nutrition affects sarcopenia specifically. Therefore, experts suggest for seniors to add vitamin D and long-chain polyunsaturated fatty acids to their diets in order to retain muscle.