But Rohm, who now co-owns Circuit Works in L.A. (where she trains four days a week) tells Us she never felt pressure to slim down quickly.
The size 4 actress also got serious in the gym with Jenny Craig fitness consultant Christopher Ross, who coached Sullivan through strength training sessions twice a week.
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"Once you start working out, you want to eat better," Sullivan -- who also jogs 3 to 6 miles five days a week -- tells Us. "Then you're like,Inflatable Obstacles, Is that burger really worth it?"
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"There are all different shapes and sizes of beauty," she says.
How'd she do it? She began running for 45 minutes six days a week and cut sugar and dairy from her diet.
According to Rohm,MLB Jerseys, it took her nearly a year to get her size 6 body back.
"We just didn't eat vegetables before," Sullivan -- who ran her first 5K in June -- says of family meals. "And now we have vegetables every day."
Determined to get her pre-baby body back, the King of Queens alum implemented a 1,200 calories per day diet via Jenny Craig.
"Six months after, I was still wearing maternity clothes," the actress, 37, confesses.
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Rohm, however, tells Us she had a more difficult time losing the 70 pounds she gained in 2008 while pregnant with daughter Easton, 2.
"I didn't know how to lose weight!" Sullivan, 40, recently admitted to UsMagazine.com. The comic -- who gave birth to her second son, Beckett, last August -- was trying to drop the 35 pounds she gained while pregnant.
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"It's exhilarating," she says of her new lifestyle. "I've really changed!"
Nicole Sullivan and Law & Order star Elisabeth Rohm are looking trimmer than ever -- but losing their baby weight didn't exactly happen overnight.