After welcoming her second child, daughter Jaxie Taylor McKee, Mackenzie quickly got back to her normal size, sharing a photo of herself on Instagram in which she looked to have never been pregnant at all, and now, she's kicking her exercise plan into full-gear.
Earlier this week, she discussed the plan on Twitter.
"And went on a short jog.... not far but my first jog since I had a baby," she told fans on March 5.
At the time she shared the before and after photos of her stomach post-baby, Mackenzie told fans that she was ready to resume working out, but since it had only been a couple of weeks since she delivered her baby, many fans worried she was putting her body at risk.
In cases where a mother has a C-section, which Mackenzie did, working out is typically restricted for at least 6 weeks -- and for Mackenzie, it hasn't yet been 6 weeks since she gave birth. So, seeing her working out so soon is a bit of a concern.
That being said, every body is different and Mackenzie surely wouldn't do anything that would cause herself harm.