On "The Biggest Loser," Bob Harper helped people transform their physical health. But the fitness trainer is nursing an emotional wound.

Harper, who served as a trainer and later host on the hit NBC reality competition series, opened up about his 2017 heart attack, including the reaction of his costar Jillian Michaels, in an Aug. 14 interview with The Guardian. Michaels served as a fellow trainer alongside Harper for much of the Emmy-nominated series' 16-year run.

In February 2017, Harper suffered a heart attack during a workout in New York City. He told TMZ at the time that after he collapsed at the gym, a doctor who was there performed CPR on him.

In his interview with The Guardian, Harper said that while many of his "Biggest Loser" colleagues reached out after his medical ordeal, Michaels notably did not.

"We weren't besties, but we were partners on a television show for a very long time," Harper told the British outlet, adding that the absence "spoke volumes to me."

USA TODAY has reached out to representatives for Michaels for comment.

Despite the emotional fallout, Harper said he "would not expect Jillian Michaels to do anything other than what she wants to do."

How Bob Harper's heart attack changed his life

In a December 2017 essay for Today.com, Harper reflected that his heart attack on Feb. 12 of that year was "a day that changed my life forever."

"I have always been what some would categorize as a Type A person. I have been driven, and I have been focused," Harper wrote. "I knew that I would be working out almost every single day. I knew that my diet would be on point. I knew that I would be burning the candle at both ends. I have always loved structure and discipline."

However, Harper said the health crisis inspired a shift in his outlook toward "appreciation and gratitude," rather than constant productivity.

"I know how short life can be. I know that it could all be taken away in the blink of an eye," Harper added. "Now when something triggers me, I try to say to myself, 'Who cares!!' It just doesn't matter. I know that I'm not perfect, and I know that life is a process. I just take it one day at a time. And that feels good to me."

Contributing: Jayme Deerwester, USA TODAY

This article originally appeared on USA TODAY: Bob Harper accuses Jillian Michaels of not reaching out after his 2017 heart attack

Reporting by Edward Segarra, USA TODAY / USA TODAY

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