Fitness and lifestyle expert Jackie Warner begins Thintervention with eight pampered clients who are unhappy with their weight.

Week two begins with basic training, which does not produce such great results. Jackie surprises the clients when she pairs them up for the week to support each other through the weight-loss process.

After several heated exchanges, Jackie arranges a dinner for the clients to resolve their issues.

The contestants embark on a three-mile hike and hunky firefighters put them through a workout. Fed up and exhausted, a group of contestants dare to lash out at Jackie.

Jackie gets tough when she starts to suspect her clients are lying in their food and workout logs. Will a lie detector test prove they have been cheating?

As the clients begin to shift the pounds, Pussycat Dolls founder Robin Antin leads a sweat-filled dance class, urging the group to get in touch with their `inner sexy'.