How the 'Biggest Loser''s Alison Sweeney Lost Her Baby Weight

"The Biggest Loser" host Alison Sweeney gave birth in January to daughter Megan -- and she returned to work only eight days later! Being around all "The Biggest Loser" contestants inspired her to want to look good for the season finale. She tells Us magazine how she dropped her 25-pound baby weight gain -- and ET has a sneak peek of Ali's story in the magazine's issue featuring hot moms.

"I didn't take a long maternity leave because I wanted to get back at it and see what my new life was going to be like," she explains. "If I took a [long maternity leave], I would have to play catch-up."

The mother of two -- she also has four-year old son Benjamin -- tells the magazine that her goal was to wear a size-four dress for the May 12 finale of the weight-loss show. After giving birth, Ali was a size eight, so she had four sizes to lose.

"I was able to go back to the treadmill two weeks after Megan was born," she tells the magazine. "I'm a very goal-oriented person. I kicked it into high gear and busted my butt, so I got to my goal."

That said, Ali admits she still has more weight to lose. Like most of us, it is those final few pounds that are difficult to shed.

"This journey is going to be longer than I originally anticipated," she says. "I think I did really well at getting rid of most of it right away, but the final six or seven pounds that I am working on are going to be the hardest."

Of course, the "Days of our Lives" star -- she plays Sami Brady -- was also at an advantage because she stayed in shape during her pregnancy, getting pregnancy exercise advice from trainers Jillian Michaels and Bob Harper. In fact, once her doctor gave her the green light, she tells the magazine, she went back to taking spin classes with Bob on Saturdays.

"You want to die," she says of his workouts. "Last week he almost made me throw up, like, three times."

For the specifics of Alison's diet and workout routines, pick up a copy of Us magazine on newsstands today.