Amy Cremen

It's all about families in the new edition of The Biggest Loser, which features four husband-and-wife teams and four parent-adult child teams trying to lose weight through diet and exercise as they compete for a grand prize of $250,000. Trainers Bob Harper and Jillian Michaels fly around the country, surprising their teams with the news they've been chosen for the show. Then it's off to The Biggest Loser ranch in California, where the contestants get a wake-up call from the show's doctor about what ages their bodies really are vs. their chronological ages because of obesity. Then the eight teams compete in their first challenge -- and the lucky winner gets immunity from this week's elimination. Alison Sweeney hosts the hit weight loss series.

This week, the contestants take a road trip to one of the most beautiful places in the world - the Grand Canyon! On the way there, they stop by a convenience store for a temptation challenge with host Alison Sweeney that will provide the winning team a much more luxurious trip for their scenic getaway. Once they arrive at the Grand Canyon, they have to figure out how to work out with no gym and no trainers. Later, the family teams compete for an amazing prize in a kayak challenge on the Colorado River before heading back to the ranch, where medical problems threaten to sideline one contestant. Then a surprise shake-up at the weigh in makes for the most difficult and emotional elimination so far. Trainer Bob Harper and Jillian Michaels also star.

The contestants get to bid on the percentage of body weight they think theyll lose this week, and the highest bidding team can win $10,000 -- but only if they reach their weight loss goal. Then its off to a wild sprint and slide challenge, with the winning team earning a phone call home. Later, Chef Rocco DiSpirito drops by to teach the contestants how to shop for and make healthy, tasty and affordable meals before an elimination round sends another team packing. Alison Sweeney is the host, and trainers Bob Harper and Jillian Michaels also star.

It's the last episode before the season finale, and time for the final four contestants to reflect on their weight loss journeys and the amazing progress they've made. They'll try on their former "big" clothes and watch highlight videos with their trainers showing just how far they've come. Then, in their final challenge of the season, the contestants will have to carry all the weight they have lost as they race around a track, shedding one week's weight loss at each pit stop until they cross the finish line. Later, at the final weigh-in, two players fall below the yellow line, and then make their heartfelt pleas to viewers as America will once again decide which of the two will become the third finalist at the season finale.

This week, the contestants are left in the dark - literally - during a wild baked goods temptation, with the winner gaining considerable power that could completely change the competition. Later, host Alison Sweeney wakes the contestants up to gather them for the challenge, which will last from sun up to sundown - the longest challenge in Biggest Loser history. One contestant struggles with a decision about whether to stay at the ranch or go home, and then an elimination round sends another contestant packing. Trainers Bob Harper and Jillian Michaels also star.