How much exercise is too much for pregnant women? That question was thrust into the spotlight after CrossFit posted a photo of a pregnant woman lifting weights on its Facebook page.

The woman working out, former bodybuilder Lea-Ann Ellison, captioned the photo: "8 months pregnant with baby number 3 and CrossFit has been my sanity. I have been CrossFitting for 2 ½ years and … strongly believe that pregnancy is not an illness, but a time to relish in your body's capabilities to kick [butt]." (Via Facebook / CrossFit)

ABC reports Ellison has plenty of weight-lifting experience: "Lifting as much as 190 pounds before her pregnancy, seen here in these Facebook pictures hoisting 75 pounds out of an abundance of caution."

The photo received thousands of likes, shares and comments. But not all of them were positive — and that was surprising to Ellison. One woman left a comment saying: "This is actually sickening, I hope pregnant [women] around the world do not do this kind of crap." (Via WPIXFacebook / Crossfit)

The photos can certainly be surprising. But the question here: Is Ellison’s weightlifting safe for a pregnant mother and her unborn baby? Medical experts say beliefs about the issue have changed in just the past few years.

The director of gynecology at Norwalk Hospital applauded Ellison for her workout, listing its benefits.

"She's reducing her child's future risks of developing obesity, diabetes and heart disease. … That said, please consult with your obstetrician to be sure you and your pregnancy are fit for your exercise program." (Via Growing Your Baby)

But the chairman of St. Louis University School of Medicine called the move a risk to both mother and child.

"When lifting weights … you divert blood flow from internal organs, including the uterus, to your muscles. That can prevent oxygen from getting to the baby. He compares it to stepping on the umbilical cord for 20 or 30 seconds, or however long you are exerting yourself." (Via CNN)

Still, experts do agree on a few rules for prenatal fitness: Expectant mothers should avoid exercises that require lying on their backs, as that can interfere with circulation. They should also avoid exercises that could cause them to fall or injure their abdomens, like horseback riding or skiing. And pregnancy isn't the time to try out a new form of exercise. (Via KidsHealth)

Ellison isn’t the only mom who’s done extreme workouts in her third trimester.

In 2011, a pregnant woman completed the Chicago marathon the same week she was expected to deliver the baby. Her doctor gave her permission to run half the race and walk the other half. Shortly after the race, she went into labor. (Via CBS)

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