It's the last week on the ranch for the final four contestants, and time to celebrate just how far they've come on their weight loss journeys. They'll return to the Los Angeles Coliseum where their journey began for a challenge requiring them to put all of their lost weight back on and drop it incrementally at 16 stops as they did each week, while running up and down the Coliseum steps. The winner gets a cash prize plus a valuable weigh-in advantage when the stakes have never been higher. The finalists also watch emotional journey packages with their trainers, revisiting the memorable milestones of their time at the ranch. 'Today' show lifestyle and fitness correspondent Jenna Wolfe visits as guest trainer, leading the contestants while pregnant through an intense, 'no excuses' workout, while Bob Harper puts the other three trainers - Dolvett, Jennifer and Jessie - through an intense workout of his own. And season 15 contestant Ruben Studdard appears in a 'Challenge America' segment before the final weigh-in at the ranch reveals the three finalists of season 16 who will be competing for the grand prize of $250,000 and the title of 'The Biggest Loser.'.

Contestants from this season reunite and reveal how much weight they've lost; the at-home winner is revealed; the grand-prize winner is announced.

Bob Harper, the longtime Biggest Loser trainer who has been with NBC's popular weight-loss series since Season 1, will take on an exciting new role - and have a much bigger presence this season - when he also becomes the host of The Biggest Loser. Harper will continue to offer his training expertise to contestants at various points throughout the season. Dolvett Quince and Jennifer Widerstrom will also be returning for the 17th season, training eight contestant teams of two in an exciting return to team-versus-team competition.