We can all expect to become weaker as we age, but you can markedly delay this inevitable loss of muscle strength by having a regular exercise program and following the same anti-inflammatory lifestyle rules that are recommended to help prevent heart attacks (Ageing Res Rev, 2021 Jul;68:101344; Front Genet, July 2, 2021), arthritis and many other diseases. This anti-inflammatory lifestyle has also been associated with greater protection from developing severe disease in the current epidemic of COVID-19 (Brit J Sports Med, Sept 16, 2021;55(19):1099-1105).

Older people who suffer from severe loss of muscles (called sarcopenia) are far more likely to have high levels of the markers of inflammation, measured with blood tests such as CRP, SED rate and adiponectin (Aging Clin and Experiment Res, August 2017;29(4):745-752). Sarcopenia is found in other conditions associated with chronic inflammation, including:
• having excess body fat (J Gerontology A Biol Sci Med Sci, 2011;66:888-895; Curr Gerontol Geriatr Res, 2012;2012:216185)
• eating a pro-inflammatory diet that raises blood sugar levels (J Gerontology A Biol Sci Med Sci, Jan 2012;67A(1):74-81)
• being diabetic (Med J Aust, 2016;205(7):329-333)
• having low vitamin D levels (Molecular Aspects of Medicine, Dec 2008;29(6):407-4140)
• not exercising (Euro Soc for Clin Invest J, 2017;47:600-611)
• having any chronic disease

What is Inflammation?
Your immune system helps to heal wounds and to protect you from infections, but it is supposed to dampen down after an infection has passed or an injury has healed. If your immune system stays overactive, it can use the same cells and chemicals to attack your own tissues, which is called inflammation. It can punch holes in arteries to start forming plaques that can lead to heart attacks, it can damage the genetic material in cells to increase risk for cancers, and it can accelerate the loss of nerves to cause debilitating muscle weakness. An overactive immune system can cause muscle cells to break down through loss of energy-producing mitochondria and increased cell death (Clin Calcium, 2017;27(1):45-52; Int J Mol Sci, Apr 12, 2010;11(4):1509-26).

If inflammation is a major cause of muscle loss, treatment should include exercise, which decreases inflammation by dampening down your immune system. Competitive masters athletes 40-80 years old, who train 4-5 times a week, lose far less muscle size or strength than their non-exercising peers (The Physician and Sportsmedicine, October 2011;39(3):172-8). Eighty-year-old men who still compete in sports have been found to have more muscle fibers than inactive younger men (Journal of Applied Physiology, March 24, 2016). At this time the most effective way to decrease the rate at which you lose muscle size and function is to exercise regularly.

Inactivity Causes Rapid Loss of Muscle Size and Strength
If you inactivate a leg by putting it in a cast, you lose a significant amount of muscle size in just four days (Nutrition, Acta Physiol (Oxf), March 2014;210(3):628-41). Prolonged periods of inactivity due to bed rest, injured nerves, casting or even decreasing the force of gravity cause loss of muscle tissue (Med Hypotheses, 2007;69(2):310-21). In one study, it took only two weeks of not using their legs for young people to lose a third of their muscular strength, leaving them on par with people 40-50 years older. Six weeks of aerobic retraining after two weeks of immobilization restored their leg lean mass and aerobic capacity but did not fully rehabilitate leg strength (J of Rehab Med, June 2015).

My Recommendations
I believe that every healthy person should have a progressive resistance program as part of their regular exercise program. It can help to stave off disability and disease. If you have never lifted weights before, you should first check with your doctor for any potential problems and in the beginning, seek out instructions on progressive resistance training. See Weight Training for Middle-Aged and Older People
Resistance Exercise You Can Do at Home

Caution: Check with your doctor before starting a new exercise program or changing the intensity of your existing program.