Is Peloton a 'Big' Problem For Heart Health?

The "Sex and the City" reboot, "And Just Like That," dropped on Thursday and, with it, there are a lot of questions about a pivotal scene that happens early in the new series.

In it, Carrie Bradshaw’s husband John Preston (also known as Mr. Big) has a heart attack after a vigorous class on his Peloton bike. (Peloton isn’t named in the show, but it’s clear what he’s riding.) Mr. Big had experience with riding his bike—he told Carrie at one point that this was his thousandth class—but he also had a history of heart issues. In season six of "Sex and the City," he had a “routine” heart operation.

The tragic scene has led some people to question whether Mr. Big’s death was caused by exercise, and it was also addressed in the show. While getting ready for Big’s funeral, Steve Brady questions his wife, Miranda Hobbs, on whether Big should have even been on “that bike.”

"He was on that bike for over a thousand rides," Miranda said. "He got the OK from his cardiologist. Exercise is good for the heart."

Peloton has already spoken out about the scene. Suzanne Steinbaum, a cardiologist who is on Peloton’s health and wellness advisory council, told the Los Angeles Times that Big’s death was likely due to his “extravagant lifestyle.”

“I’m sure SATC fans, like me, are saddened by the news that Mr. Big dies of a heart attack,” Steinbaum said. “Mr. Big lived what many would call an extravagant lifestyle—including cocktails, cigars, and big steaks—and was at serious risk, as he had a previous cardiac event in season six. These lifestyle choices and perhaps even his family history, which often is a significant factor, were the likely cause of his death. Riding his Peloton bike may have even helped delay his cardiac event.” 

Steinbaum continued, “The lesson here is, KNOW YOUR NUMBERS! It's always important to talk to your doctor, get tested, and have a healthy prevention strategy. The good news is Peloton helps you track heart rate while you ride, so you can do it safely.”

Peloton released an ad on Sunday in response to the scene. In it, Chris Noth, who plays Mr. Big, is sitting by a fire with Peloton instructor Jess King, who plays Big’s favorite cycling instructor Allegra in the show. “I feel great,” Noth says in the ad. “Should we take another ride? Life’s too short not to.”

Then, Reynolds chimes in with a voiceover that said, “And just like that, the world was reminded that regular cycling stimulates and improves your heart, lungs, and circulation, reducing your risk of cardiovascular diseases. Cycling strengthens your heart muscles, lowers resting pulse, and reduces blood fat levels. He’s alive.”

Still questions keep circulating on social media. Is it safe to exercise when you have a heart condition? And can something like this happen in real life? Here’s what you need to know.

Can This Happen in Real Life?

Unfortunately, yes, it’s possible to die of a heart attack while exercising.

“Exercise increases the heart's demand for oxygen,” Jason P. Womack, MD, chief of the division of sports medicine and associate professor in the department of family medicine and community health at the Rutgers University Robert Wood Johnson Medical School, told Verywell. “While this is beneficial in most people, anyone with underlying cardiovascular disease may stress the heart beyond its capacity which can lead to heart-related death.” 

But, “even though this situation happens every so often, the exact mechanism by which it occurs is not really well understood,” Rigved Tadwalkar, MD, a board-certified cardiologist at Providence Saint John’s Health Center in California, told Verywell.

It could be due to increased stress on the walls of the arteries, spasms in the arteries, or disruption of plaque that lines the walls of the arteries, he said.

“In the grand scheme of things, it’s fairly rare, but it’s more likely to happen in somebody who has a known history of heart disease or risk factors for heart disease,” Tadwalkar said.

Womack noted that “men have a higher risk of heart disease compared to women and this increases as they get older.”

Mr. Big’s lifestyle choices, like smoking cigars, also wouldn’t help. “Tobacco use increases risk, as does elevated levels of cholesterol and high blood pressure,” Womack said.

And, Big's previous heart issues “shows that there is an underlying cardiovascular disease that would increase your risk of another event.” 

Is It Safe to Exercise if You Have Heart Issues?

Whether it's safe to exercise with preexisting heart issues depends on the person.

“For anyone with a history of heart issues or history of a heart attack, they should exercise under the supervision of their physicians,” Womack said. “There is testing that can be done to demonstrate what is a safe level of exertion for their heart.”

In general, weight training is considered safe and has a low risk of causing heart-related problems, Womack said, provided the weight you're lifting isn’t “excessively heavy.”

How well your heart disease is managed or where you are in your treatment course matters, too.

“Generally speaking, if a patient’s treatment is well managed, people can exercise safely,” Tadwalkar says. “We encourage people to get out there and be the best version of themselves, and exercise usually plays a role in that.”

Some people may need to modify their exercises but that “depends on testing,” Womack said. “Exercise stress tests can help to determine at what level a person can exercise safely,” he added.

If you've had a heart attack or other cardiovascular issue, your doctor will likely want to monitor you for a bit, Jennifer Haythe, MD, co-director of the Women's Center for Cardiovascular Health at Columbia University Irving Medical Center and cardiologist at New York-Presbyterian/Columbia, tells Verywell Health. "Most people should undergo supervised cardiac rehab after a heart attack and your doctor will set guidelines on what is appropriate," she says.

One big caveat, Tadwalkar said, is with certain forms of congenital heart disease. “Some people with hereditary syndromes are more prone to changes in rhythm,” he explained. In those situations, exercise may not be recommended or may only be recommended on a mild level.

“Your best bet is to speak with your cardiologist or physician if you’re concerned,” Tadwalkar said.