How does extreme physical activity affect longevity?

While everyone knows that regular exercise is important for a healthy life, some previous studies have shown that intense workouts may have the opposite effect.

A new study recently published in the British Journal of Sports Medicine suggests that people who participate in extreme sports may live longer.

Researchers tracked a select group of elite runners who could run a mile in under 4 minutes and found that they could live an average of five years longer than the average population.

Andre La Guerche, PhD, a sports cardiologist and director of the Heart, Exercise and Research Trials (HEART) lab supported by the St. Vincent's Institute of Medical Research and the Victor Chang Cardiology Research Institute, and lead author of the study, explained to Medical News Today:

"There is a strong belief in society that you can overdo it with exercise. We thought this was an opportunity to explore a physical feat that was once considered impossible and could be very taxing on the body. There was an assumption that such feats could have a negative impact on the body. So this was an opportunity to dispel that myth."

Elite runners can live longer than the average person

For this study, La Guerche and his team focused on the lifespan of a group of the first 200 elite runners to run a mile in under 4 minutes. The runners came from 28 different countries in North America, Europe, Oceania, and Africa.

All study participants were born between 1928 and 1955 and were, on average, 23 years old when they ran a mile in under 4 minutes.

Of the 200 participants, 60—or 30%—died, leaving 140 people alive at the time of the study.

The researchers found that the average age at death for study participants was 73, but the average age for surviving elite runners was 77.

At the end of the study, the scientists found:

• Overall, those who ran a mile in under 4 minutes lived about five years longer than their expected life expectancy, based on age, gender, year of birth and ethnicity.
• Those who ran a mile in under 4 minutes in the 1950s lived an average of nine years longer than the average population.
• Participants who ran a mile in under 4 minutes in the 1960s lived an average of 5.5 years longer, and in the 1970s, they lived about 3 years longer.

The results are similar to those seen in elite cyclists.

La Guerche said they weren't surprised by these findings in elite runners, as they are consistent with several other publications, such as studies of Tour de France cyclists, where longer lifespans are also observed.

"Our study aimed to find out how exercise impacts elite athletes over the long term," la Guerche said.

"We know that elite athletes have bigger hearts because of their sustained aerobic training, and there was a perception that this might impact their health and longevity, but we found the opposite. Five extra years of life over the average is very significant, especially when we found that many of these runners not only lived longer, but they were healthier. They lived better and longer."

“This is one of many projects we are conducting that look at cardiovascular and health changes associated with exercise,” he added. “We continue to evaluate the factors that lead to beneficial outcomes in those who exercise regularly.”

How can you live longer if you are not an elite athlete?

Of course, not everyone can run a sub-4-minute mile or be an elite athlete. So how can you apply these results to your own exercise regimen to hopefully extend your life?

"While we are urged not to extrapolate in science, I personally use this data as inspiration to try to emulate as many of the 4-minute miller's lifestyle factors as possible: good nutrition, moderate alcohol consumption, dedication and regular, intense exercise," la Guerche said.

"While I can't necessarily share the genetic predisposition that probably also contributes to elite speed, the rest I can try to achieve."

Jennifer Wong, MD, a board-certified cardiologist and medical director of noninvasive cardiology at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, California, who was not involved in the study, said, "I think it highlights the importance of exercise, maybe not necessarily at this extreme level, but just any exercise that's beneficial for cardiovascular health and ultimately, hopefully, prolongs life in that way."

Tracey Zaslow, MD, a board-certified pediatrician and pediatric and adult sports medicine specialist at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, California, who was not involved in the study, said more research is needed to determine how best to extrapolate these findings.

“While I wouldn’t recommend changing your practice based on this one study, it may be reassuring to know that there may not be as many risks of ‘overdoing it’ as previously thought. I would encourage readers to take inspiration from these elite athletes to improve their fitness by aiming for moderate exercise as often as possible,” Zaslow said.

More research is needed on exercise types and durations

In further discussion, Wong said she thinks the findings of this study make sense: this level of fitness early in life is associated with longevity.

“It’s also encouraging because sometimes we hear that extreme exercise causes problems,” she continued.

"I'd like to see more studies showing a correlation between exercise later in life. It also makes a difference when someone continues to exercise, and this study specifically looked at someone's ability at one point in their life, but it doesn't say what happens later or who continues to exercise. There might be a big difference between people who continue to exercise later in life."

Zaslow told MNT that she found the study interesting because it contradicts many other studies that have previously shown that extreme exercise can increase the incidence of cardiovascular events and changes in the structure or function of the heart.

“The next steps are to further study other types of athletes, as this study was exclusively about runners,” she said. “Also, comparing a wider range of athletes to determine if there is an optimal amount or intensity of exercise to best promote longevity.”