Credit: Mackenzie Douthit on Instagram

Teen Mom 3's Mackenzie Douthit gave birth to a bouncing baby girl just under a month ago, and you know what that means... the time has come for this lady to get her six pack back! It shouldn't be too hard considering that she already has a completely flat stomach just three weeks after giving birth. Sigh.

Anyone who watched the MTV reality show knows that Mackenzie is a fitness addict who eats well and works out on the regular. Not only is this gal a professional cheerleader, she does yoga and goes running to stay fit, and she's finally ready to ease back into her pre-pregnancy workout routine! Most doctors advise new moms to wait on exercise until around six weeks postpartum, but it looks like Mackenzie's gotten the go-ahead from her OB GYN, and recently went on her very first run.

"And went on a short jog...." Mackenzie tweeted on March 5. "Not far but my first jog since I had a baby."

Mackenzie didn't just "have a baby" — she had a C-section, which basically amounts to major abdominal surgery! The fact that this girl is already up and running (literally) just a few weeks after her operation is amazing, but let's hope she doesn't push herself too hard. Mackenzie is known for being super active, so hopefully she'll listen to her body and rest when she needs to!

Are you surprised that Mackenzie is working out so soon after having a kid? Hit the comments and let us know what you think!