Michelle Aguilar

The contestants get a blast from the past this week with visits from season five winner Ali Vincent and season six winner Michelle Aguilar, both filling in as host while Alison Sweeney is on maternity leave. The contestants are also surprised by the arrival of some old friends, whose return promises to shake up the competition. And while one player is sidelined by medical issues, the rest compete in a balance and endurance challenge that finds each contestant standing on a platform, suspended six feet over a pool. One by one, the lines supporting the platform are removed, making it harder to stand, until only the winner is left standing. Later, Bob has last chance workouts at the beach before the weigh in, which is followed by a surprising elimination. Trainers Bob Harper and Jillian Michaels also star.

The final four contestants go home for 30 days, reunite with friends and family and experience firsthand the challenge of continuing to make diet and exercise a priority back at home. Contestants also learn from host Alison Sweeney what their final challenge of the season will be running a full marathon when they return to the ranch for their final weigh-in. Completing the full 26.2 mile course will be their toughest challenge yet, but cheering them on along the way are some past season “Biggest Losers” grand prize winners Ali Vincent and Michelle Aguilar, plus “at home” winners Jim Germanakos, Heba Salama and Bernie Salazar. And as an added incentive, each player who finishes the marathon will get $10,000 to donate to the charity of their choice. Later, it’s the very last “last chance workouts” with trainers Bob Harper and Jillian Michaels before a final weigh in determines who the two definite finalists will be and which two contestants fall below the dreaded yellow line, leaving America to vote which one will be the third finalist to compete for the grand prize of $250,000.

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.

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.

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.