The Biggest Loser' host Alison Sweeney opened up about a confrontation with Jillian Michaels that went down on-screen.

For those less familiar, let's take a look at who Jillian Michaels is and what she's been up to since the Biggest Loser wrapped – and what we know so far about her decision not to appear in the Netflix docuseries,

Michaels was a trainer on “The Biggest Loser” for seasons 1, 2, 4-11, 14, and 15. She often motivated contestants by yelling at them or insulting them. In one clip from “Fit for TV: The Reality of the Biggest Loser,” Michaels pushes a woman to keep exercising even after she vomits on a treadmill.