Losing It Fast

They're breaking speed records, but celeb moms like Denise Richards know that getting back in shape after baby – whether it's the first or fourth – takes sweat and sacrifice


"My mom said after she had my brother that was the best her body had ever looked," Spears (from left, while pregnant and one month after giving birth) told PEOPLE in June. "Having a child inspired her." Spears, who had Sean Preston on Sept. 14, is already getting back in shape. One major tip for new moms: "Sleep is important in keeping the body fat off," says celeb trainer Gunnar Peterson.