Isaac "Chism" Cornelison

In this season of "no excuses," this week's challenge addresses the excuse "I can't lose weight on my own." Trainers Bob Harper and Dolvett Quince are suspended over water in a wild dunk tank-like challenge in which the red and black teams have to use their strength to keep a weight from landing their trainer in the pool. The losing team has to do without their trainer all week until the last chance workout. Once the losing team is determined, one contestant admirably steps up to lead their group while their trainer is away, with none of them aware that he is secretly watching how they do in his absence. Later, a very heated elimination sends another player home after a tense weigh-in to see how both teams did this week.

This week kicks off with a Chinese buffet temptation that will give the winner complete control of how contestants will be matched up for a face-off challenge in the gym -- and also give them a two-pound advantage to use or give away. Later, trainers Bob Harper and Dolvett Quince coach the contestants through a wild water-transfer challenge that will reward the winning team with the most coveted prize of all -- video chats home. And one player makes a shocking decision that stuns everyone before another contestant is sent packing following the weigh-in. Alison Sweeney hosts the series.

The stakes are high this week as the red and black teams compete in a fierce battering ram challenge that will give one team exclusive rights to the gym, while the losing team has to find other creative ways to burn calories. Both trainers - Bob Harper and Dolvett Quince - struggle with certain contestants who they feel aren't giving it their all, making it tougher for both teams to get the weigh-in win each one wants. Alison Sweeney hosts the series.

The stakes are high this week when representatives of each team bid on the percentage of weight they think their team will lose at the weigh-in. The highest bidder gets a five-pound advantage if they hit their number at weigh-in -- or lose the advantage to the other team if they don't hit their mark. "The Biggest Loser" nutritionist teaches the contestants how to shop for healthy food, and the black and red teams square off in a fast-paced challenge in which they have to turn an anchor wheel to retrieve puzzle pieces and then race against the clock to put the puzzle together. And later, the players get a sobering wake-up call when Dr. Huizenga reveals their real "inner ages," before the weigh-in leads to another player going home.

A lively challenge that involves bouncing medicine balls on a trampoline to get them over a wall tests the speed and coordination of both the black and red teams as they vie for a valuable prize - the ability to choose which player's weight won't count at this week's weigh-in. Then it's a blast from the past when aqua team siblings Adrian and Daphne, who were eliminated before they even got to the ranch in episode one, come back to weigh-in and reveal whether they've lost enough weight to return to the competition. And a few personality clashes add tension in the house before the players decide which contestant will go home this week. Alison Sweeney hosts the series, and trainers Bob Harper and Dolvett Quince also star.

"The Biggest Loser" returns with a bang for season 13 when the contestants arrive at the ranch and get one of the biggest surprises ever in the series' history. They arrive in teams of two -- including mother/daughter, father/son, brother/sister and husband/wife, all eager to change their lives together. But they're shocked to discover that they will not only be split up -- they will also be competing against the person they came with. They'll be pushed out of their comfort zones in a way they have never been before -- and one team won't even make it on to the ranch -- as the season of "No Excuses" begins. The players all have different excuses for why they never lost weight before. So the season of "no partners" will also be a season of "no excuses" -- as week in and week out, all the typical reasons for not getting in shape will be addressed. Alison Sweeney hosts the series, and trainers Bob Harper and Dolvett Quince also star.