The trainers are back for their biggest challenge yet. In this season they tackle obesity in the township of Ararat, which is considered one of Australia's most overweight communities.

It's day two of boot camp and with the chosen contestants passing the physical test it's now time for the mental test. If they want to make it into The Biggest Loser house, they must put everything on the line and face their fears.

In a shock twist the contestants are paired up to face the 'Punisher' Challenge, running the steps of the Opera House. The two pairs that come last will be up for elimination.

The contestants scamper downstairs in their PJ's to find Commando and Shannan waiting to pick their training teams. After the contestants are split, it's time for their first training sessions in the house.

It's now time for the contestant's first team challenge as Blue versus Black. It's a 'Chains of Pain' challenge at the beach whereby each team are chained together, and must complete three under digs and three over wall climbs.

Nerves are setting in as contestants get set for their first competitive weigh-in. Later at the house it's temptation time, and contestants have the chance to win 30,000 dollars, but what's the catch?

Everybody heads out to a dockyard for this week's challenge, and up for grabs, is a very big and very valuable reward. However, there is a shock twist as cracks start to appear in the teams.

Everybody heads out to a dockyard for this week's challenge, and up for grabs, is a very big and very valuable reward. However, there is a shock twist as cracks start to appear in the teams.

During the weekly weigh-in there's a surprise from Hayley. Meanwhile, the decision from the temptation challenge is weighing heavily on one contestant's mind.

It's the elimination aftermath, and one team in particular is not coping very well. Meanwhile, 'The Fridge' makes a game-changing return to the competition, especially for one contestant.

It's now time for this week's challenge, as teams arrive at the YMCA University of NSW pool to see ten treadmills lined up leaning over the water. The challenge is simple - to be the last one standing.

It's last chance training before the weigh-in. However, one contestant is unable to train after being rushed to hospital. After the weigh-in, two contestants are up for elimination, but who will go?

Hayley meets the contestants to announce a Biggest Loser first. Meanwhile, the Fridge holds a surprise for one contestant which will change their time in the house.

The contestants head outside for a good old fashioned 'stacks on' challenge and up for grabs are letters from home for the winning team.

It's last chance training, and for one contestant it becomes too much and they have a meltdown during the session. Meanwhile, someone is called out on the scales for not working hard enough.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.

Twelve overweight contestants battle the bulge to lose the most weight before their rivals do, in order to avoid being voted off the show. Their goal? A more healthy future, $200,000 cash, and the title of Australia's Biggest Loser.