This story originally appeared on KERA Breakthroughs.
After completing the first swim in the history across the Atlantic Ocean, the first words out of Ben Lecomte’s mouth were “Never again.”
Now this Frenchman is jumping into the Pacific for a swim expected to take five to six months.
“I’m not a fast swimmer,” Lecomte said over Skype in January, laughing.
But, boy, this Texas transplant is dedicated.
“Swimming is a passion, so it just comes back,” he says. “You cannot just push it away.”
Lecomte, 48, says he’s worried about the future for his kids. He’s diving back in the ocean to focus attention on environmental problems.
During The Longest Swim, he’ll collect data on the Pacific – the microbes, the trash – but also on himself. On how his heart holds up for eight hours of freestyle every single day. This data will go to Dr. 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.’”
Dr. Paul Thompson is another cardiologist curious about the ways hardcore exercise affects the heart.
“If you look at people who run marathons or do triathletes, one of the things that’s been noticed is scarring or some fibrosis in their heart,” Thompson says. “Right where the two sides of the heart join each other — the septum.”
Thompson is chief of cardiology at 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.
There’s a second area of concern, Thompson says.
“It’s been shown in a couple of studies now that people who are lifelong term endurance athletes have more coronary artery calcification than you would expect for their risk factors,” he says.
In regular people, calcification usually means a buildup of cholesterol – not something you’d expect to find in people swimming the English Channel, running the Sahara, or tackling Iron Man competitions.
Thompson says there’s likely an explanation — and most of us don’t have to worry about either scaring or calcification.
Remember, the question here isn’t whether exercise is bad. It’s whether there are diminishing returns, and if there’s such a thing as too much.
“We don’t think that long-term exercise is dangerous because long-term live longer than other people.” Thomson says. “But are there changes that happen in the heart? We think there are. Our point is to investigate and figure out what’s going on.”
Which brings us back to Ben Lecomte – the guy swimming the Pacific – and the tricky task of monitoring his heart from the middle of the Ocean. UT Southwestern’s Levine has a plan, and connections with NASA to help.
It’s something called remote guidance echo.
Levine has used this technology to study astronauts’ hearts on the international space station.
But let’s stay on Earth for now. In the ocean scenario, a small portable echo machine will be on the wooden support boat traveling with swimmer Lecomte. Once a month, Lecomte will turn it on and use a satellite phone to call a laboratory at Johnson Space center.
That’s where he’ll get coached, remotely, on how to use 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.
“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.”
So what’s the significance of a little inflammation?
“For most people, it really is of no consequence,” Levine says. “I think there can be consequence, though, I think people who have pulmonary hypertension, other kinds of heart disease.”
He hopes studying Lecomte’s heart will help reveal why extreme exercise changes the heart, and understand the outer-limits of human capacity.