High-Intensity Workouts During Pregnancy: Safe or Sorry?

Understanding risks, and taking precautions, are key to staying safe while getting your prenatal sweat on.

pregnant-woman-weightlifting Tina Rupp

The many benefits of exercising during pregnancy range from less weight gain to a lower risk of gestational diabetes and a general better mood. Overall, it's a good idea. But recently a story about an eight-months pregnant mom doing a high-intensity exercise called CrossFit created a major online stir, many questioning its safety. Known for its passionate following, CrossFit features high-intensity heavy lifting performed at a fast pace. Its one-size-fits-all approach has garnered many critics for anyone, pregnant or not.

Lea-Ann Ellison, 35, posted a photo of herself performing an Olympic lifting maneuver two weeks shy of giving birth to her third child. The photo generated over 2,000 comments, mostly bashing Ellison for "taking stupid risks." Ellison defended herself, saying she'd been doing CrossFit for two and a half years prior to her pregnancy and felt her workouts helped her stave off back pain and other common pregnancy complaints.

So how safe is it, really, during pregnancy?

"In general, women can stick to their usual workout program during the first trimester," says John Higgins, MD, director of exercise physiology at Memorial Hermann-Texas Medical Center. "Exercise intensity should not exceed pre-pregnancy levels, however." Since Ellison had been doing Crossfit for years before her pregnancy, and she moderated the amount of weight she lifted, her workout fit into these parameters.

Changes that take place during pregnancy can put women at higher risk of some injuries, however. "Pregnant women need to consider several things," says Shannon Clark, MD, associate professor in the department of obstetrics and gynecology at the University of Texas Medical Branch (UTMB) in Galveston.

Key Considerations

Joint risks
"Looser joints and a changing center of gravity as the pregnancy progresses alters a woman's sense of balance, making her more susceptible to injuries such as sprained ankles and knees," says Clark.
Be safe: For CrossFit or any high intensity workouts, find an instructor knowledgeable on how to alter workouts to accommodate pregnant women. "These workouts should be tailored to the pregnant individual, rather than a group," says Clark.

While CrossFit workouts do not typically last for prolonged periods, the fast pace and intensity create a potential for dehydration. "Dehydration can cause preterm uterine contractions, and in the worst-case scenario, lead to preterm labor," says Clark.
Be safe: Stay well hydrated. Eight or nine cups of water a day is recommended during pregnancy, on [lm] average, but fluid needs should be adjusted for intensity and duration of the workout.

Direct trauma
Lifting heavy weights at a fast pace increase risk of direct abdominal trauma, falling or injury.
Be safe: Use proper form, modify form and poundage and steer clear of others lifting weights near you.

RELATED: Set Yourself Up for Prenatal Fitness Success

Decreased blood flow to the uterus
A prolonged or strenuous workout can potentially decrease blood flow to the uterus, and occur most often with long distance running, says Clark.
Be safe: If a woman is doing these types of workouts it's important to monitor the growth of the fetus periodically to ensure proper growth, says Clark.

Intra-abdominal pressure
Straining to handle heavy weights causes increased intra-abdominal pressure, says Clark. "This could potentially cause uterine contractions or rupture of the membranes surrounding the uterus."
Be safe: Modify the amount of weight you lift to avoid increased pressure.

Signs to stop immediately
Dizziness, back or abdominal pain, vaginal bleeding or excessive shortness of breath are signs to stop right away and check with your doctor, says Higgins. "The American Congress of Obstetrics and Gynecology (ACOG) recommends that normally healthy pregnant women may continue an already-established exercise regimen, but you should check with your doctor if you're exercising for the first time."

RELATED: Once you're cleared for postnatal exercise, snag some inspiration from these 10 Seriously Fit Chicks of CrossFit (starting with a new mom-and-baby profile).

Linda Melone, CSCS