First aired on September 20, 2011 The 15 new contestants are dropped off in the middle of the California desert, before meeting with Alison.
Out next is the first newcomer, former professional tennis player-turned-certified fitness trainer Anna Kournikova, wearing Bob's old blue color.
However, as the blue team continues to struggle, Anna and the other trainers, along with the rest of the contestants, run out to meet them and they all cross the line again together.
The next day, the contestants meet their trainers at the front door of the gym to begin their first workout, and all teams are training at the same time.
She particularly notices Debbie and Johnny's lack of motivation and habits of frequently making excuses and asking for breaks, all of which Anna refuses, and at one point, Johnny decides to leave, but later decides to get back into the gym to finish the workout.
Antone clearly struggles with what he has become in comparison to his previous athleticism, and breaks down, crying on the floor, just 10 minutes into the workout.
Later on, in the middle of the night, Becky receives a phone call at 3:15 am, notifying her that her father had died of heart failure.
Antone has also made significant progress from the first workout, but Dolvett decides at one point to kick Patrick out of the gym because of his self-doubt.
Anna compares this experience to "playing at Arthur Ashe stadium in front of 20,000 people."
In the contestant catch-up segment, Debbie has lost 24 pounds, and is much more active, frequently exercising with her daughter, including taking part in her son's dance classes.
This decision apparently caused some conflict, as the red team seemed to think John showed a lack of respect towards them.
Antone falls off the spin machine from pushing himself so hard, and struggles with his lack of fitness in comparison to his previous days as an athlete.
At the 12 noon-2 pm time slot, Anna tailors Bonnie's workout to help with her knee injury, but Johnny is struggling and gives up very quickly in all of his exercises.
During the workout, Jessica talks to Dolvett about struggling with her past, and how her previous partner encouraged her to gain weight to combat his jealously.
Dr. Huizenga is on the ranch to deliver health test results to the contestants, with the trainers there to support them at his request.
In Bonnie's case, after having her stomach stapled, she lost over 100 pounds, but the majority of that weight was muscle rather than fat, and as a result, she is in worse shape than before her surgery.
As a result, the blue team loses the weigh-in again, and decide to send Johnny home due to his lack of motivation throughout the week.
In the contestant catch-up segment, Johnny has lost 59 pounds, and is enjoying the chance to play with his grandchildren.
First aired on October 11th, 2011 Week 4 starts with the aftermath of the Red Team meeting with Dolvett having voted out Patrick.
Morning comes and both Red and Blue are shown to be working out while the Black Team get introduced to Hannah from Season 11, in amazing shape.
Bonnie struggles with her knee and can't run with Anna believing she is mentally scared but physically capable.
In the end, the red team won the challenge and gets two weeks worth in the Biggest Loser resort.
Now it is time for Sunny to weigh-in and in order for the black team to be safe, she needs to lose more than 6 lbs.
Among the young group, Jessica wins and picks Dolvett, Ramon is stuck with Anna and after the previous weigh-ins confrontation he is not happy about it.
In the middle group Antone wins and chooses Bob, Sunny picks Anna and that leaves John with Dolvett.
Judges are Olivia (season 11 winner) and Devin Alexander (author of all the Biggest Loser cookbooks).
Winner receives a 1 lb advantage at the weigh-in, their recipe will be included in the new Biggest Loser Quick and Easy recipe book, and the team gets one-on-one time with Olivia to talk about life after the Biggest Loser and maintaining their weight-loss.
At home, Joe weighed 235 pounds and since he missed out on riding on roller coasters for 4 years and so, he took his daughter to the amusement park 4 times.
After massages, they each get a makeover from the Ken Paves salon and see Iris, a Cirque du Soleil show, with a loved one.
After the weigh-in, Becky and Vinny are eliminated, leaving Antone and John to face Ramon for the grand prize of $250,000.