Isaac "Chism" Cornelison

"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.

This week, a surprising turn of events shakes up the competition, and the contestants compete in a rough and wild short version of a “Tough Mudder” competition. But they won’t be doing it alone - with them will be the show’s three most recent winners John Rhode, Olivia Ward and Patrick House. Host Alison Sweeney helps motivate the remaining contestants by telling them the player with the highest percentage of weight loss at the weigh-in will win a Ford Escape SUV. Later, the players stroll down memory lane with the trainers and watch video journeys of how far they’ve really come from their first day on the ranch before an emotional weigh-in determines which player will walk away with a brand new car.

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 eight remaining contestants head to the tropical paradise of Hawaii for an action-packed week that will address the excuse "I can’t lose weight on vacation." After being warmly welcomed to Oahu with a luau, the players compete in a trivia challenge that awards the winner a cash prize which can be spent on a menu of items. Next it’s off to the breathtaking Kualoa Ranch where "Jurassic Park" was filmed and there the contestants race through a challenge involving tikis and leis for the coveted prize of immunity. Later, a young woman who epitomizes "no excuses" - real-life "Soul Surfer" Bethany Hamilton - teaches the contestants and trainers how to surf. Then at Pearl Harbor, with the USS Missouri in the background, the contestants weigh in to reveal whether they were able to lose weight on vacation before another player is sent home. Alison Sweeney hosts the series and trainers Bob Harper and Dolvett Quince also star.

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.