Sports medicine physician and fitness instructor Jordan Metzl, M.D., teaches a seminar for medical students at Cornell University called “prescribing the medicine of exercise.” And when it comes to exactly how to administer this wonder-drug, “the most time-efficient exercise for most people is running,” he says.
While it’s not completely clear how much running contributes to weight loss—some studies show it’s more effective than walking, while other researchers argue “you cannot outrun a bad diet”—reams of research backs its other health perks.
“There are immediate daily benefits for your life today,” and if you keep it up, you can ward off more serious illnesses for years to come, says Mark Cucuzzella, M.D., professor at West Virginia University School of Medicine and author of Run for Your Life. On average, runners may live anywhere from three to six years longer, research suggests.
Here are a few of the biggest benefits to your body when you take to the road, path, or trail.
A sharper brain
In a small study of young adults, seven weeks of running intervals boosted not only aerobic fitness but also cognitive flexibility—the brain’s ability to transition quickly between tasks. Another found hitting the treadmill, even at a slower speed, for just 15 minutes improved people’s ability to memorize lists of words on a cognitive test.
What’s more, “it’s the only method proven to prevent Alzheimer’s,” Dr. Metzl says—indeed, in a 2014 study, people who ran more than 15 miles per week had about a 40 percent lower risk of dying of the condition over an 11-year period.
One potential mechanism: Running seems to boost levels of something called BDNF, or brain-derived neurotrophic factor, which stimulates the growth of new neurons, Dr. Cucuzzella says. In addition, the brains of endurance athletes seem to be wired differently, suggesting running has the power to strengthen neural connections linked to higher-level brain functions.
A stronger cardiovascular system
Yes, sudden cardiac deaths sometimes occur during long-distance races. But overall, regular runners had a 30 percent lower risk of dying of heart disease over a 15-year period, found one large study of more than 55,000 people. And the more moderate-to-vigorous exercise you get, the lower your levels of biomarkers linked to heart disease, including inflammatory compounds C‐reactive protein and interleukin‐6.
It takes more than a strong heart to pump blood throughout the body. You also have 60,000 miles of blood vessels that have to function well to deliver nourishing, oxygenating fluids to your muscles and organs. Fortunately, running helps there too—older athletes’ blood vessels function as well as those of people half their age.
Your endothelial function—the ability of the tissue lining your blood vessels to contract and relax properly—also seems to improve the more you stride. One contributing factor? Running—especially If you log your miles outside in the sun—prompts your body to produce more nitric oxide, a powerful vasodilator, Dr. Cucuzzella says.
A lower risk of diabetes
The more you run, the more energy-generating mitochondria you sprout inside your cells, and the better those tiny power factories function. Mitochondria play a key role in helping your body transform glucose into energy, in part by regulating secretion of the hormone insulin. So, the more mighty mitos you procure, the better your body is at regulating your blood sugar and warding off type 2 diabetes, Dr. Cucuzzella says.
Research backs him up: Lawrence Berkeley National Laboratory scientists found that over six years of follow-up, runners decreased their risk of developing diabetes by 12 percent compared to people who didn’t work out.
And, if you already have diabetes, running can improve your blood glucose control and keep you healthier, longer. In one decade-long study, people with the condition who ran or walked were less likely to die of everything from heart disease and kidney disease to sepsis and pneumonia.
Less jacked-up joints
Nearly every runner’s had to deal with friends and family expressing concern for their delicate knees. “The idea that you’re going to run your knees into the ground sounds good, but it’s not true,” Dr. Metzl says.
Why? Runners’ leaner frames put less pressure on joints, and repetitive loading of the knees and hips actually strengthens cartilage, Dr. Metzl says. Also, new evidence suggests running may decrease levels of inflammatory chemicals implicated in the development of degenerative joint disease.
Less chance of developing—or dying—of cancer
Exercising regularly can reduce your risk of approximately 13 types of cancer, Dr. Metzl says. Running specifically has proven powerful in both reducing the risk of a new diagnosis and improving the prognosis of those affected by the disease.
For example, according to a study published in Medicine & Science in Sports & Exercise, people who used running to meet the government’s physical activity guidelines had a 61 percent reduced risk of kidney cancer, and cut that rate even lower if they ran more.
Another, in the International Journal of Cancer, suggested women with breast cancer had a lower risk of dying of the disease if they ran regularly than if they walked instead. And either activity seems to reduce the risk of dying of brain cancer.
Scientists are still working to untangle the exact mechanisms. Reduced levels of hormones like estrogen and insulin in regular runners may play a role. Another theory, supported by animal research, holds that the epinephrine released while running stimulates the production of natural-killer immune cells.
A slowdown of the aging process
Not only do runners often live longer, they also tend to spend their later years in better health—a phenomenon called, in catchy medical terms, compression of morbidity.
In one 21-year study, runners had lower scores on test measuring disability, whereas non-runners experienced significant difficulty performing at least one task associated with regular daily functioning.
Running may even keep you younger deep down at the cellular level. In a 2018 study published in the European Heart Journal, endurance exercise—which includes running—increased both the production of an enzyme called telomerase and the length of telomeres, DNA sequences that cap our chromosomes and protect cells from age-related decline.
By Cindy Kuzma