Is pregnancy an ‘excuse’ to let your body go?

C'mon, new moms. Get your butts to the gym! No excuses for hanging onto that pregnancy weight, right? Right?

Tracy Anderson, fitness trainer to the stars, suggests women have to stop making excuses when it comes to returning to prepregnancy shape. According to the celebrity website Radar Online, Ms. Anderson, who counts Madonna, Gwyneth Paltrow and Jennifer Lopez among her clients, gained 30 pounds (13.6 kilograms) during a recent pregnancy – and promptly lost it all six weeks after giving birth.

"A lot of women use pregnancy as an excuse to let their bodies go, and that's the worst thing," Ms. Anderson told Du Jour magazine.

The toned mother of two, who has created an exercise DVD series called The Pregnancy Project, added: "I've seen so many women who come to me right after [having children] with disaster bodies that have gone through hell, or they come to me years later and say, 'Oh, my body is like this because I had three kids.'"

It did not take long for others to slam Ms. Anderson for setting unrealistic expectations.

"What an idiot!" Majid Ali, a nutritional expert, told Radar Online. "Sure, most choose to try and get back to their prebaby weight as soon as they can but a few things get in the way like returning to work, or having two or more kids, or a household and no help, so any extra time is used up for cleaning and child care."

Hormonal changes, which may slow a woman's metabolism, can hinder weight loss, Mr. Ali added. Pregnancy-related insulin resistance can also make weight loss challenging.

One commenter wrote: "I could barely have time to shower in the first six weeks [after giving birth] nevermind exercise, not to mention I couldn't even imagine leaving [my] baby the first several weeks of life. I guess her priorities are different than mine."

Even renowned hardbody Jillian Michaels has softened her stance on postbaby workouts since becoming a parent.

"I used to tell moms that for the sake of their well-being they had to put themselves first," Ms. Michaels said, according to BabyCenter.com. "But I know now that's not always possible."

Pressure on women to strive for the "postbaby sexy body" appears to be increasing. At the same time, there are plenty of health reasons for getting back into shape as soon as possible after giving birth.

According to the Mayo Clinic, women can expect to lose more than 10 pounds (4.5 kilograms) during childbirth. (Besides the weight of the baby, that includes the placenta and amniotic fluid.) With diet and exercise, and a reasonable goal of losing 1 pound (0.5 kilogram) a week, it could take six months or longer to return to prepregnancy weight.

Is Tracy Anderson's swift postpregnancy weight loss inspiring or unrealistic?