Jillian Michaels is punching back at “The Biggest Loser” alumni who made claims against her in the Netflix documentary “Fit for TV,” which explores the “dark side of the NBC reality series.” Michaels was a fitness trainer on the weight-loss competition series from 2004 to 2011,

Rachel Frederickson astounded television audiences when she won The Biggest Loser competition in 2014.

My relationship with Jillian was flawed and was contentious because of what I just said; I was an athlete, I own a gym, I knew a little bit about what I was doing, more so than any of the other contes...