Can Extreme Exercise Hurt Your Heart? Swim The Pacific To Find Out | KUOW News and Information

Can Extreme Exercise Hurt Your Heart? Swim The Pacific To Find Out

Feb 1, 2016
Originally published on February 2, 2016 6:33 pm

Any day now, Ben Lecomte will plunge into the Pacific Ocean off a Tokyo beach toward San Francisco. He wants to become the first person to swim across the Pacific. He's already the first person to free swim across the Atlantic Ocean, without a kickboard.

No one knows how the physical feat of swimming 5,500 miles will affect Lecomte's heart, but cardiologists are anxious to find out. His swim offers a rare opportunity to study whether extreme athletic performance has a harmful effect on the heart.

After he completed the swim across the Atlantic in 1998, the first words out of Ben Lecomte's mouth were "never again."

Now this 48-year-old, French-born American is about to embark on a swim expected to take five to six months.

"I'm not a fast swimmer," Lecomte says. But boy is he dedicated. "Swimming is a passion," he says. "You cannot just push it away."

Lecomte, who lives in Austin, Texas, is diving back into the ocean to focus attention on environmental problems. He's worried about the future for his kids. During the swim, he will collect data on the Pacific, including the microbes and trash he encounters. People can follow along on his Facebook page, The Longest Swim.

He will also collect data on himself, including how his heart holds up for eight hours of freestyle every single day. This data will go to Benjamin Levine, a cardiologist at UT Southwestern Medical Center and director of the Institute of Exercise and Environmental Medicine at Texas Health Resources.

"My question has always been, how much exercise do you need to do to injure the heart?" Levine says. "Since Ben was planning to swim across the Pacific Ocean, we thought, hey, this might be a good opportunity."

After all, we're told more exercise is better — and generally, it is. Yet several studies of extreme endurance athletes have called that idea into question.

People who run marathons or do triathlons can have some scarring or fibrosis in the center of the heart, says Paul Thompson, chief of cardiology at Hartford Hospital in Connecticut. "Right where the two sides of the heart join each other — the septum."

This scarring at the septum is worrisome, Thompson says, particularly for people who have an underlying genetic condition that weakens the heart muscle.

And there's a second area of concern. "It's been shown in a couple of studies now that people who are lifelong endurance athletes have more coronary artery calcification than you would expect for their risk factors," Thompson says.

Calcification, meaning a buildup of calcium in the heart, is not something you'd expect to find in people swimming long distances, running ultramarathons or tackling Ironman competitions. There could be a genetic explanation to both the calcium issue and the scarring, Thompson says. So he advises people to study up on their family history and see if there have been cases of sudden death, then weigh the benefits and risks of extreme exercise.

"We don't think that long-term exercise is dangerous, because long-term endurance athletes live longer than other people," Thompson says. But Thompson does want to figure out what's going on.

Which brings us back to Ben Lecomte and the tricky task of monitoring his heart from the middle of the ocean.

Using technology that NASA uses for monitoring astronauts on the International Space Station, UT Southwestern's Levine will be able to monitor Lecomte's heart during his swim. It's a small echo machine, like an ultrasound for the heart, that will be on the support boat traveling with Lecomte. Once a month, while resting on the boat, Lecomte will turn the machine on and use a satellite phone to call the Johnson Space Center.

Someone there will tell Lecomte how to position the probe to give himself an echocardiogram.

From his desk in Dallas, Levine will see images of how fast Lecomte's heart is contracting, how quickly the blood flows in and out of the valves, and any stress where the two sides of the heart meet.

His prediction?

"I think when he comes back he'll have signs of a little inflammation or irritation right where the right and left ventricle connect," Levine says. "That's what we see in some other of these elite long-endurance athletes, and I think that's what we'll see in Ben."

For most people this inflammation is really of no consequence, Levine says. But for some people — for example, those who have pulmonary hypertension or other kinds of heart disease — it could cause problems.

He hopes studying Lecomte's heart will help reveal why extreme exercise changes the heart and determine whether there's a limit to how much exercise the human heart can handle.

Ben Lecomte is not worried. He thinks his heart can handle the enormous ocean, some 20-foot-high waves and the occasional shark.

Copyright 2017 KERA. To see more, visit KERA.

RENEE MONTAGNE, HOST:

In Japan on a beach near Tokyo, swimmer Ben Lecomte is set to plunge into the ocean. He wants to be the first to swim across the Pacific Ocean. He's already crossed the Atlantic, and this 5,500-mile swim offers a rare opportunity for doctors to study extreme athletic performance and its effect on the heart. From member station KERA, Lauren Silverman reports.

LAUREN SILVERMAN, BYLINE: After finishing the first free swim in history across the Atlantic Ocean, Ben Lecomte uttered two words - never again. Now this Frenchman is jumping into the Pacific for a swim expected to take five to six months.

BEN LECOMTE: I'm not a fast swimmer.

SILVERMAN: But, boy, is this Texas transplant dedicated. Lecomte grew up in France and now lives in Austin.

LECOMTE: Swimming is a passion. You cannot push it away.

SILVERMAN: At 48 years old, Lecomte says he's worried about the future for his kids. He's diving back in to focus attention on environmental problems. During the swim, he'll collect data on the Pacific, the microbes, the trash, also on himself - on how his heart holds up for 8 hours of freestyle every day. This data will go to a professor of cardiology at UT Southwestern and Texas Health Resources, Dr. Benjamin Levine.

BENJAMIN LEVINE: My question has always been, how much exercise do you need to do to injure the heart? And so, since Ben was planning to swim across the Pacific Ocean, I thought, hey, maybe this would be a good opportunity.

SILVERMAN: It sounds a bit crazy. After all, we're told more exercise is better, and generally, it is. Yet, several studies of extreme endurance athletes have called that idea into question. Dr. Paul Thompson is another cardiologist curious about the ways hardcore exercise affects the heart.

PAUL THOMPSON: If you look at people who run marathons or good triathletes, one of the things that's been noticed is scarring or some fibrosis in their heart right where the two sides of the heart kind of join each other. We call it the septum.

MONTAGNE: Thompson is chief of cardiology at the Hartford Hospital in Connecticut. He says this scarring at the septum is worrisome, particularly for people who have an underlying genetic condition that weakens the heart muscle.

THOMPSON: A second area of concern is that it's been shown in a couple of studies now that people who are lifelong endurance athletes have more coronary artery calcification than you would expect for their risk factors.

SILVERMAN: Calcification, meaning a buildup of calcium in the heart, is not something you'd expect to find in people swimming long distances, running ultra marathons or tackling Ironman competitions. Thompson says there could be a genetic explanation, so he advises people to study up on their family history of sudden death to weigh the benefits and risks of extreme exercise.

THOMPSON: We don't think that that long-term exercise is dangerous because long-term endurance athletes live longer than other people, but are there changes that happen in the heart? We think they are. Our point is to investigate them and figure out what's going on.

SILVERMAN: Which brings us back to Ben Lecomte and the tricky task of monitoring his heart from the middle of the ocean. UT Southwestern's Levine has a plan.

LEVINE: We're doing something called remote guidance echo.

SILVERMAN: Levine has used this technology to study astronauts' hearts on the International Space Station. In the ocean scenario, a small echo machine - it's like an ultrasound for the heart - will be on the support boat traveling with swimmer Lecomte. Once a month, he'll turn on the machine and use a satellite phone to call the Johnson Space Center. Someone there will tell Lecomte how to position the probe to give himself an echocardiogram.

LEVINE: Take a breath in, out, hold it. Press the red button - great.

SILVERMAN: From his desk in Dallas, Levine will see images of how fast Lecomte's heart is contracting, how quickly the blood flows in and out of the valves and any stress where the two sides of the heart meet. The research could help show whether there's a limit to the amount of exercise the human heart can handle.

LEVINE: Maybe if you swim every day for eight months and get all the way across the Pacific Ocean, the heart looks just fine. Under those circumstances, I'd probably say to most people, don't worry about going for a swim.

SILVERMAN: Lecomte is anything but worried. He thinks his heart can handle some 20-foot-high waves, an enormous ocean garbage patch and the occasional shark. For NPR News, I'm Lauren Silverman in Dallas. Transcript provided by NPR, Copyright NPR.