Fitness trainer and Biggest Loser host Bob Harper says he is recovering from a serious heart attack that left him unconscious for two days.
Harper tells TMZ he was working out in a gym in New York City this month when he collapsed. He says a doctor who also was in the gym performed CPR on him.
The 51-year-old says he spent eight days in a New York hospital and has not yet been cleared to fly home to Los Angeles.
Harper told TMZ that his heart condition is genetic because his mother died from a heart attack.
But sources have told US Weekly that the star "pushes himself too hard."
Last week, Harper posted a cryptic message to Instagram showing a candle, a pile of photos and the caption, "My word of the day ... LUCKY."
The trainer is reportedly not back to his usual training regimen, but has posted photos to social media of him walking around New York.
Harper has been a fixture on all 17 seasons of the US version of The Biggest Loser.
He served as a trainer on the show from 2004 to 2015. He took over as host of the reality weight loss program last year.
Harper got his start as a celebrity trainer before landing a gig on The Biggest Loser in 2004.
He also appeared on the first three seasons of the Australian version of the show.
In 2010, the star launched his own health and fitness website mytrainerbob.com where subscribers can discuss weight loss and receive coaching.
Along with fellow Biggest Loser trainers Jillian Michaels and Dolvett Quince, Harper was embroiled in a controversy in 2014 when one contestant lost a shockingly huge amount of weight.
Eventual winner Rachel Frederickson weighed 47kg after starting the show at 117kg.
Her appearance at the show's finale caused an uproar among viewers and health professionals.
Appearing on the Rachael Ray show soon after, he said, "What people don't understand is, when the contestants leave to go home..."
"They're in charge of themselves. So, I had not seen her until that night, and so when she walked out, I was just kind of like, whoa. And I've been on the show since the beginning, forever."