Two new trainers and a compelling new twist deliver a game-changing season like nothing viewers have seen before when season 11 premieres with twenty-two contestants -- eleven family and friend teams of two. After the first challenge, contestants are given the unprecedented opportunity to choose whether to work out with trainers Bob Harper and Jillian Michaels at the ranch - or work out at a secret location with two unknown trainers and get four weeks of immunity. What ensues is a riveting ride of intense emotions, surprising turns and "can't miss" moments as the two groups fight their weight loss battles separately with two sets of trainers equally committed to giving these players a new lease on a healthier life. The contestants include an Olympic gold medalist, identical twin policemen, a pastor who wants to spare his overweight son from the challenges he faced because of obesity, and a woman who has lost pregnancies because of her weight and wants more than anything to be a mother. Alison Sweeney hosts the series.

The "unknown trainers" are finally revealed, and both will share their personal stories that led them to "The Biggest Loser." Their contestants, "the unknowns," confront one player they feel isn't working hard enough, and later, "the unknowns" and the ranch contestants square off for a pop challenge. The winning player from each group will get a delicious healthy dinner prepared by Chef Curtis Stone, and compete for a coveted 2 lb. advantage at this week's weigh-in. Later, Dr. Huizenga gives "the unknowns" startling news about their health, and one player is surprised to learn they have the highest percentage of body fat in the group. Meanwhile, trainers Bob Harper and Jillian Michaels single out a few of their contestants to find out what really led to their weight gain, and then the ranch contestants meet host Alison Sweeney for a water-carrying challenge that will give the winner the sole vote at this week's elimination. Later, a surprising weigh-in -- which results in shocking numbers for one team -- disappoints the trainers in a big way, leading to the elimination of one player they feel isn't ready to go home.