For years, Bob Harper and Jillian Michaels appeared to have great chemistry onscreen while filming "The Biggest Loser" together. But a new docuseries about the NBC weight-loss competition has fans wondering if the dynamic duo actually got along in real life.

Despite sharing the gym for more than a decade, Jillian Michaels and Bob Harper didn't leave as Biggest Loser friends — a revelation that became quite clear after his shocking 2017 widowmaker heart attack that almost claimed his life.

Bob Harper didn’t hear from Jillian Michaels after his heart attack in 2017. In a new interview with The Guardian, Harper, 59, said many people from “The Biggest Loser” reached out to him after the near-fatal health incident — but not Michaels, 51.