Black or Blue Shirt? Like previous weeks, Week 8 on the Ranch began with a "pop challenge" — but the stakes in this one were about as high as they could get. The players met Alison on a field, who stood beside two rows of shirts: one black (representing my team, of course) and one blue (representing Bob's). The challenge was a race to see which team would be the first to complete 100 up-downs (an old-school football drill in which you drop to your belly on the ground, then jump up again — over and over). This being The Biggest Loser, of course there was an extra element of fun: The players had to do their dropping and jumping in a big puddle of mud. Mmmm. Each couple chose one person to compete, and the winning couple would get to choose their team and trainer. The last-place couple would be split up and put on opposing teams, and everyone in the middle would be leaving their fate to the flip of a coin. Sione got out to an early lead, but Tara eventually overtook him to win. Sione, Dane, and Mike finished after her, leaving Helen and Kristin to battle it out. Kristin eventually reached 100 before Helen, ensuring that she and her mother Cathy would get to stay together.

The New Order: With the challenge over, it was time to choose sides. Since Helen came in last but was alone on the Ranch, she was automatically switched to my Black Team. Tara and Laura chose to stay on my team, and they put on their black shirts. Alison flipped a coin for Filipe and Sione, and it turned up black. Both so attached to Bob, they were not at ALL happy to be coming to train with me. Next, my girls Mandi and Aubrey got switched over to Blue, as did Dane. Next, Ali flipped a coin for Mike and Ron. It came up black, but since there was only one spot left on my team, they had to split up. Mike came over to my side, and Ron stayed with Bob. That left no choice for Kristin and Cathy, but luckily for them, they were more than happy to stay with Bob. Bob and I couldn't believe it when we saw how much the teams had changed, and it wasn't easy for anybody to swallow at first. Bob took it especially hard, but in the end, we all sucked it up and got to work with our new teams.

Going the Extra Mile: As if the contestants hadn't been through enough this week, Alison presented them with the longest challenge in Biggest Loser history. The teams went to the gym, where there were two bicycles set up on stationary trainers. Over the next 24 hours, the teams would go head-to-head in a relay race, and the team that racked up the most miles on their bike would win a three-pound advantage at the weigh-in, plus custom bikes for each member of the team. Both teams got off to a strong start, but as they switched off through the night, they got worn down pretty fast. These bikes weren't like spin bikes at the gym — their seats were narrower and less comfortable, and they didn't have the foot straps that make it easier to pedal. By morning, everyone was pretty beat, and Mandi floated the idea of calling a truce. Sione announced that he did not want to quit, and his speech inspired everyone to dig in and finish the thing. At the end of the 24 hours, the Blue Team had cycled 264 miles, and my Black Team had gone 301.9! To put that in perspective, that's more than the distance from L.A. to Las Vegas!

Tomorrow Night: Part Two of this week's show airs on NBC at 8 p.m. ET — be sure to tune in to see the weigh-in and find out who gets eliminated!