Amber Miller ran the Chicago Marathon while pregnant at 39 weeks; immediately after completing the race, she gave birth. Despite backlash against her seemingly inappropriate and reckless behavior, it turns out that expectant mothers aren’t doing anything wrong by running.

U.S. Olympian Alysia Montano has become the most recent one to prove that. Montano ran an 800-meter dash at the USATF championship in California at 34 weeks pregnant. “I know there is a lot of stigma and really, the world is ignorance, behind pregnant women and exercising,” Montano told CBS LA. “And the truth is, it’s good for the mom and the baby.” The 28-year-old finished last in her heat, but she was proud to have finished the race with a belly.

Don’t necessarily go out and run intense marathons while pregnant if your body isn’t used to workouts at that level — but being idle isn’t exactly the best alternative. Dr. Francis Chang is an OBGYN at Good Samaritan Hospital, and he believes that Montano was able to pull off such a race because her body is athletically prepared for it. “We tell them that whatever level of exercise they’re used to, that they can continue exercising at that level,” Chang told CBS LA. “The only thing I worry about if it’s direct trauma to the belly or any falling.”

The thought of a pregnant woman running can cause cringes — is it really okay for the baby to be shaken up like that? In fact, running is safe for pregnant women. “Running is safe anytime — during the first, second and third trimester — if you are having an uncomplicated pregnancy,” Dr. Sheeva Talebian, a maternal health expert, told Women’s Running. “You should not run if you have complications like elevated blood pressure or, in some cases, multiple gestation, that would cause an obstetrician to advise no high-impact exercise.”

In fact, some doctors recommend running or exercising in moderation during pregnancy. It’s important, however, to be wary of a few things: overheating, especially in the first trimester, and falling — particularly in the second and third trimesters. “All of the same reasons you normally exercise — heart health, stress reduction, weight maintenance, lower blood pressure — are reasons to run during pregnancy,” Talebian said. “Additionally, women who exercise while pregnant have lower rates of diabetes and preeclampsia, and they are less likely to gain an unhealthy (and potentially dangerous) amount of weight.”