This week, one eliminated contestant returns and the remaining players are split into four teams - red, blue, green and black. Each team will be led by one of the four trainers - Bob Harper, Jillian Michaels, Cara Catronuova and Brett Hoebel. While Bob takes his team to spin class and Jillian takes hers to work out at the beach, Brett leads his group on a hike and Cara heads to a boxing ring and has one of her players fight against a longtime boxer. Later, the four teams square off in a difficult challenge involving ropes and weights, and then gameplay at the weigh-in doesn't turn out the way one contestant expects, and another player is sent home. Alison Sweeney hosts the series.

This week kicks off with a pop challenge in which contestants have to estimate the length of a mile. The winning team gets a night out on the town, Hollywood style, while the other players have to stay behind and clean the ranch. Later, the teams race to light up a "Biggest Loser" board in a challenge that gives a stiff penalty for the losing team - no votes at the elimination. Then one trainer gets shocking news at the weigh-in, and after an emotional elimination, host Alison Sweeney delivers some very exciting news to the contestants.