In a recent meta-analysis combining 16 studies and data from more than 1.5 million subjects, muscle-strengthening activities were associated with a nearly 20 percent lower risk of cardiovascular disease, cancer, diabetes, lung cancer, and mortality for any reason.
“Strength training provides multiple health benefits independent of aerobic exercise,” said Daniel J. McDonagh, a researcher at the University of Minnesota School of Public Health and co-author of a large study that looked at the effects of aerobic and muscle exercise. a strengthening exercise on mortality. Adding some muscle also improves physical fitness and bone mineral density and reduces the risk of musculoskeletal injuries.
Running, swimming, playing soccer, and other aerobic exercises do a lot for the cardiovascular system—our heart and blood vessels—but they don’t do much for overall muscle mass or strength.
Perhaps most importantly for health, studies have found that strength training improves the body’s response to insulin and therefore leads to better blood sugar control after meals—which means a reduced risk of diabetes or insulin resistance, conditions that can damage the heart and cardiovascular system by thickening the heart wall and increasing the formation of arterial plaque.
Also, emerging evidence shows that contracting skeletal muscle produces myokines, which are small strings of amino acids that exist between the muscle and the rest of the body, which can help regulate various metabolic processes leading to better cardio- metabolic health, says McDonough. German researchers reported last spring that “by stimulating skeletal muscle in a certain way, we can harness this cross-talk and improve health.”
Because aging and inactivity tend to reduce muscle mass, resistance training is even more important for older adults because it helps slow the natural loss of muscle mass with age, McDonagh says. Reducing muscle loss with age is critical to maintaining independence and helping older adults stay active. It also reduces the risk of chronic diseases due to disability and lack of activity.
Strength training appears to have a positive effect on brain health and function, possibly reducing the risk of dementia and Alzheimer’s disease, experts say.
Michael Valenzuela is a researcher at the University of New South Wales and one of the leaders of a study that looked at the effect of resistance exercise on cognitive function and brain structure in 100 subjects with mild cognitive impairment. He found that strength training seemed to protect the areas of the brain, specifically the hippocampus, that are commonly targeted by Alzheimer’s.
This could give strength training a potential role in disease prevention, Valenzuela says. “We also found that these changes led to better overall cognitive outcomes in the older people who received the training, so it’s not just a fluke,” he says.
A 2022 study in JAMA Network Open, based on the Canadian Longitudinal Study on Aging, found that having low muscle mass was associated with faster future cognitive decline in adults at least 65 years old. Researchers theorize that greater muscle mass may lead to more physical activity and cardiorespiratory fitness, leading to greater blood flow to the brain.
So how much strength training is enough?
The federal physical activity guidelines for Americans recommend two or more strength training sessions each week. Ideally, sessions should include four to six different exercises that use as many muscle groups as possible (legs, thighs, back, abs, chest, shoulders and arms). For each exercise, perform 10 to 12 repetitions two to three times.
“We found that just 1-3 hours a week of moderate exercise – brisk walking and/or vigorous aerobic exercise such as [high intensity interval training] training—and just 1-2 times a week of strength training significantly reduced the risk of death from all causes,” says McDonagh.
Given that walking to the bus or the store is important, most people should be able to fit in 60 minutes a week of aerobic exercise, McDonagh says. Both strength training sessions don’t have to be at the gym, he adds. These can be any form of resistance, such as gravity, hand weights, resistance bands, or even water bottles or boxes from the cupboard, or lifting grocery bags.
So cardio or weights or both? If you want to live longer, the best option is to do both, experts say.
“We consistently find that the greatest health benefits, whether it’s reduced risk of death or chronic disease or improvements in risk factors like blood pressure or cholesterol, are seen among people who do both types of exercise, not just one or the other,” said Angelique Brelentin, assistant professor of kinesiology at Iowa State University and co-author of a recent review article titled “Aerobic Exercise or Muscle-Strengthening Exercise: Which Is Better for Health?”
The review found that while aerobic exercise and muscle-strengthening exercise independently reduced the risk of death from all causes, people who did cardio and weight training realized the greatest benefit, including an estimated 40% reduced risk of all-cause mortality and 50% reduced risk of mortality from cardiovascular disease.
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