Weightlifting is no longer a sport for burly men in cavernous gyms. In recent years, there has been growing awareness that the benefits of strength training extend beyond pure aesthetics to include overall health and longevity. Lifting weights not only reduces the risk of chronic health problems but helps maintain function and independence as we age.
Strength training, also called resistance training, involves harnessing resistance as an opposing force for muscles to work against. The resistance supplied by free weights, bands, machines, or body weight pushes muscles beyond their usual capacity. This increases the production of new muscle protein, which increases strength and mass over time.
Our muscle mass and strength gradually decline with age. Age-related muscle loss, called sarcopenia, begins around age 35 at 1-2% per year, then accelerates to 3% per year after age 60. The average adult can expect to lose between 4 and 6 pounds of muscle per decade, usually replaced with fat (given the scales don’t trend down).
Sarcopenia is largely due to disuse, a product of our increasingly sedentary lifestyles as we age. Fortunately, we can reduce and reverse age-related muscle loss with regular strength training, and it’s never too late to start. We can increase strength and muscle mass well into our 80s and 90s. Studies found that older adults engaging in resistance training programs experience increased mobility and independence, reduced body fat percentage, and an overall enhanced quality of life.
Conditioned individuals who maintain their exercise regime can preserve lean muscle mass in later life. The below striking cross-sectional image illustrates this by comparing the leg muscles of a 40-year-old triathlete, a sedentary 74-year-old man, and a 70-year-old triathlete. While the leg muscles in the sedentary man have significantly atrophied and been replaced by fat, the triathlete has retained musculature similar to the younger triathlete.
Figure from Wroblewski AP, Amati F, Smiley MA, Goodpaster B, Wright V. Chronic exercise preserves lean muscle mass in masters athletes. The Physician and Sportsmedicine. 2011;39:172-178.
Resistance training improves heart health by reducing cardiovascular disease risk factors, including blood pressure and blood sugar. The 2023 Scientific Statement from the American Heart Association reported that approximately 30 to 60 minutes of resistance training per week lowers the risk of cardiovascular disease by 17%.
Stronger muscles are more efficient at extracting oxygen and nutrients from the blood, allowing blood to circulate through the body with greater ease. This lowers blood pressure in healthy and hypertensive adults, with effects on systolic blood pressure comparable to blood pressure (antihypertensive) medications.
Skeletal muscle stores excess blood glucose as fuel in the form of glycogen. Stronger muscles increase blood glucose uptake, which controls blood sugar levels and helps the body stay sensitive to insulin (the hormone that transports glucose from the bloodstream into cells). Effective blood sugar control is crucial in the prevention and management of type 2 diabetes. In observational studies, regular resistance training is linked to a 17% lower incidence of diabetes compared to not participating in resistance training.
Brawn is also good for the brain. Exercise boosts memory and cognition by stimulating the production of growth factors, chemicals that affect the growth of new blood vessels in the brain and the overall health of new brain cells. Consequently, brain regions responsible for thinking and memory tend to be larger in people who exercise regularly than those who don’t.
A 2020 study was the first to show the long-term effects of resistance training interventions in slowing the degeneration of brain areas vulnerable to Alzheimer’s disease. Participants with mild cognitive impairment were given one of three interventions—strength training, computerised brain training, or a combination of the two—for six months and reexamined 12 months later.
The study found that strength training improved overall cognitive performance and protected against the degeneration of the hippocampus, the brain’s memory hub. Participants who did not engage in strength training saw a 3-4 per cent shrinkage in the hippocampal subregions over 18 months, whereas trained individuals saw only 1-2 per cent reductions in some areas and none in others.
Strength training is medicine or, at least, it has similar effects in reducing disease risk, enhancing quality of life, and protecting against cognitive decline. In other words, strength training is not just a lifestyle choice but a prescription for a healthier, more vibrant life at any age.