4 Prenatal Fitness Lies You Tell Yourself

Don't let these common exercise myths get in the way of an active pregnancy.

A young pregnant woman sitting on a purple yoga mat GettyImages.com

Fitness fallacies spread like athlete's foot on a communal yoga mat, especially during pregnancy. To be fair, there has been a lot of game-changing prenatal fitness research in the last few years. Here, some common misconceptions, and what they mean for your workout.

Myth: It's dangerous to do ab exercises.

Fact: Core exercises, targeting your abs and pelvic-floor muscles, can minimize lower-back pain and build your strength—super helpful during labor. Avoid performing ab moves lying on your back after the first trimester. Instead, try ball crunches, planks and pelvic tilts, suggests Tatum Rebelle, a certified personal trainer and owner of Total Mommy Fitness, a prenatal exercise consulting company in Austin, Texas.

Related: A Pilates Workout for the Whole 9 Months

Myth: Exercise causes low birth weight.

Fact: Moderate exercise does not compromise a baby's birth weight. "Some studies show no effect, and others show the babies of exercising moms are slightly leaner but still well within the normal range," says Danielle S. Downs, PH.D., an associate professor of kinesiology and obstetrics and gynecology at Pennsylvania State University. As long as you don't overexert yourself, your baby should be just fine.

Related: 33 Reasons to Exercise Now

Myth: Exercising in the first tri can cause miscarriage.

Fact: Studies have found no connection between exercise and miscarriage. It's true the majority of miscarriages happen in the first trimester, but they are typically caused by genetic abnormalities of the embryo or a preexisting condition—not exercise.

Myth: Working out can make your baby overheat.

Fact: Total old wives' tale. "Exercise won't raise your core body temperature to a dangerous level," says Rebelle. "The pregnant body is great at dissipating heat and will do whatever's necessary to protect your baby."