Jessica Simpson: Gym It to Win It

Jessica Simpson: Gym It to Win It (ABC News)

To quote Ru Paul, Jessica Simpson better work it. The new mom has been hitting the gym hard since giving birth to daughter Maxwell Drew Johnson on May 1, and the sweat sessions aren't just for her "swamp a**" - the nickname she gave her backside during pregnancy.

Simpson signed an estimated $3 million deal with Weight Watchers last month to be their latest celebrity ambassador. She has big shoes to fill: Weight Watchers' last celebrity spokesperson, Jennifer Hudson, dropped several dress sizes and an estimated 80 pounds while repping the diet company. Though she's just begun her battle, Weight Watchers has faith.

"Her talent, resilience and positive outlook already make her a great role model," the company said last month. "And by deciding to trade in yo-yo dieting for a healthier lifestyle, we know she will inspire many women to join her."