During their morning workouts, the contestants look back at their amazing progress since they first set foot on the ranch. They've transformed themselves into different people, both mentally and physically, and every single one of them has become a fierce warrior. The trainers remind the contestants of just how far they've come, and they couldn't be more proud of their pupils this season.
Next, it's time for the contestants' biggest challenge yet. They'll compete in the first ever Biggest Loser Triathlon, consisting of a half-mile swim, a 12-mile bike ride and a three-mile run. The winner of today's triathlon will automatically be a finalist in next week's finale. They'll also receive a brand new Ford Fusion Energi hybrid car! The contestants take their marks at the starting line, and on Alison's cue, they're off!
Rachel clearly has an advantage, thanks to her swimming experience. David just wants to keep up with Rachel, and Bobby struggles immediately with the swimming portion of the triathlon. Meanwhile, Jennifer and Chelsea are evenly matched in the middle of the pack. Along the way, all of the contestants are surprised by their abilities. Their endurance is strong, and their bodies feel good. There's no way they could have dreamed 14 weeks ago that they would be competing in a triathlon.
Rachel finishes the swimming portion of the triathlon, but she knows that swimming is her strongest suit. She'll have to work hard to keep her lead on David. Meanwhile, Chelsea is right on David's trail in the fight for second place. Bobby trails behind in fifth place, but he's determined to finish no matter what.
Rachel manages to hold onto her lead through the cycling portion of the race. David, Chelsea, Jennifer and Bobby also finish the cycling portion of the race, and it's time for the three-mile run. Rachel bursts into tears before she even crosses the finish line. She's shocked and amazed that she accomplished this incredible feat, and she also wins a car and a guaranteed spot in the Biggest Loser finale!
David crosses the finish line second, beaming with pride and confidence. He's a different man than he was 14 weeks ago. Chelsea finishes third, feeling better than ever. The new-and-improved Jennifer crosses the finish line in fourth place, and Bobby trails in fifth place. Nonetheless, all of the contestants completed a triathlon, an accomplishment that they couldn't have imagined in their wildest dreams before coming to the ranch.
Later in the week, the trainers prepare for their favorite part of the season: They invite each contestant in one-by-one to relive their journey on the ranch. The day is filled with tears, laughs, heartache and perseverance. Most importantly, it's an incredible and undeniable reminder of just how far the contestants have come during their time on the ranch.
At long last, it's time for Season 15's final weigh-in on the ranch. Rachel already has a guaranteed spot in the finale. Of the four remaining contestants, two will be heading to the finale with Rachel, and two will be heading home. Rachel weighs in first and clocks a one-pound loss. Chelsea drops seven pounds; Jennifer sheds three pounds; Bobby ditches an astonishing 17 pounds; and David abandons 16 pounds. David and Bobby will be joining Rachel at the live finale! Unfortunately, Chelsea and Jennifer are heading home, but they're still eligible for the at-home prize of $100,000!