If you were searching for a Hollywood star who was fit, strong and healthy, Bob Harper was your guy.
Whether training contestants on The Biggest Loser, breaking a sweat to his fitness DVDs or cooking up recipes from his cookbooks, this 51-year-old was a man in more than just good shape.
But just a few days after news broke of Bob's surprise heart attack earlier in the month, fans are still trying to figure out how the fitness expert could have experienced such a frightening health scare.
"There were some warning signs in the months before this happened," a source shared with E! News exclusively. " He wasn't feeling his best, but he didn't think there was anything to be concerned about. He has never suffered from high blood pressure and didn't think he was at risk."
While his mother passed away from heart issues, our source says that she was not as healthy as Bob. And while there is a genetic connection, Bob "always tried to live his life in the healthiest way possible to avoid this kind of incident."
Through an Instagram post shared on Tuesday morning, Bob thanked fans for all their support while delivering an update on his recovery.
"I'm required to wear these monitors to see what my heart is doing throughout the day," he wrote while posing shirtless. "I feel like a robot from Westworld. Thank you all for your kindness. You have no idea how much it helps."
Fellow Biggest Loser trainer Jen Widerstrom added, "@trainerbob I think I speak for everyone when I say how truly grateful we are that you are OK, how important you are to us & this industry, and how we are all in your corner as you work back to 100% BADASS BOB."
E! News has learned that Bob remains in New York City where he has been with friends and discussing what changes he needs to do in order to avoid this from happening in the future.
"It has definitely led him to reevaluate things and try to better understand how this happened," our source shared. "Luckily, he is going to make a full recovery but obviously it is forcing Bob to make some important decisions about his future."
(E! and NBC are part of the NBCUniversal family)