Each week, Nuance goes beyond the basics and offers detailed, researched information on the latest scientific news and expert insights on a much-talked-about health topic.
According to exercise, running is your workout, which humans have been doing since the caveman days of our species. There is no shortage of evidence that running is a source of health and longevity.
It’s one of the most popular forms of aerobic exercise, and a wealth of research has linked aerobic training to health benefits ranging from reduced cancer risk to improved cognitive performance.
TO 2015 study found that even a modest amount of running (five to 10 minutes a day at a slow pace) was associated with a 28% reduction in all-cause mortality and an even greater reduction in the risk of death from heart disease.
“Runners, on average, lived three years longer compared to non-runners,” says study author Duck-Chul Lee, an associate professor of kinesiology at Iowa State University.
Long-term runners, those who stick around for six years or more, seem to experience the greatest longevity benefits, Lee says.
Stronger and faster is not always the same as healthier.
But as running became more popular, so did longer distances. More people than ever are running marathons (and even ultramarathons), leading experts to wonder if more is really better.
“Stronger and faster doesn’t always equal healthier,” says James O’Keefe, MD, cardiologist and associate clinical professor at the University of Missouri-Kansas City School of Medicine.
Designing a car to win the Indy 500 is a much different goal than designing a car to run smoothly for 500,000 miles, O’Keefe says. Similarly, building a race plan to maximize speed and stamina is not the same goal as building a race plan to maximize longevity.
“Excessive strenuous exercise can actually erase some of the longevity benefits seen with moderate exercise,” he adds.
O’Keefe was once an avid runner. But he switched to other activities (including walking) after research on him linked excessive running to poor health. One of O’Keefe’s studies found that while running modest amounts is a bulwark against disease and death, running too much actually erases those benefits.
“Stupid” runners, defined as people who ran more than 7 miles per hour and more than four hours a week, had death rates similar to those of sedentary adults, their study concluded.
Some researchers have questioned these findings. In response to the study, Martin Burtscher, MD, a professor at the Austrian Institute of Sports Science at the University of Innsbruck, noted that the study relied on self-reported pace, which could skew the findings.
Burtscher says he hasn’t seen convincing evidence that people can “overdo” running, citing another recent study that found no mortality-reducing benefit among people who did a lot of vigorous exercise.
But the study Burtscher mentioned looked at links between “physical activity” and mortality, not running. When you delve into recent research on running specifically, it has been found that running can increase a person’s risk of some health problems, especially those related to the heart.
The association between long-duration, intense resistance exercise and atrial fibrillation, a heart irregularity that can increase the risk of heart failure and stroke, is “well accepted in the scientific community,” says Eduard Guasch, MD, a researcher at heart health. at the Hospital Clinic of the University of Barcelona.
While running is incredibly good for you, even in small doses, there can be some risks associated with intense resistance training.
Guasch says it’s not yet clear how exercise can cause or contribute to heart problems. One popular theory is that large amounts of resistance exercise “reshape” the heart in ways that cause dysfunction. But Guasch says that’s still being debated. “There is no clear threshold beyond which we can confidently say that a specific athlete is at increased risk of [atrial fibrillation],” he says.
There is also some evidence that a person’s genetic predisposition to atrial fibrillation or other heart problems may make hard running especially risky. And for people with underlying heart problems, marathon running is associated with a small but measurable risk of sudden cardiac death.
The bottom line (at least for now) is that while running is good for you, even in small doses, there can be some risks associated with intense training. How much is too much? This question is hotly debated and depends on a person’s age, DNA, state of health, and various other factors. “I think the current research available shows that there are a variety of durations and frequencies that provide longevity benefits for the average individual,” says Angelique Brellenthin, a postdoctoral researcher at Iowa State who, along with Lee, studied the effects of working on life. .
Brellenthin’s research suggests an operating limit of 4.5 hours per week (up to six days per week). This fits with other recent research that has found that 40 to 60 minutes a day of vigorous exercise is probably a safe upper limit for people looking to maximize their health.
O’Keefe offers more concrete figures: “No more than 4.5 hours a week or 30 miles a week.”
There is no doubt that some experts disagree. And if you’re one of the many people who run marathons out of personal challenge, a sense of community, or sheer love of the sport, you might be heartened by the inconclusive state of the evidence. But if you’re hitting the streets primarily to improve your health, recent research suggests that less can be more.