Katherine Heigl Gets 'Back on the Exercise Train' After Welcoming Son -- See Her Hilarious Outfit!


The 38-year-old actress isn't going to let a mismatched outfit stop her from getting her fitness on.

Katherine Heigl is "back on the exercise train"!

The 38-year-old actress took to Instagram on Wednesday to announce that she's started exercising again, just seven weeks after giving birth to her baby boy, Joshua Bishop Kelley Jr.

WATCH: Katherine Heigl Shares First Photo of Son Joshua -- See the Sweet Family Pic!

"1st day back on the exercise train postpartum and I'm feeling fine! And yes I am wearing a sweatshirt with my own face on it...only sweatshirt I had that was warm enough for Utah...then of course there's the fanny pack...and the ol' Miss ski hat...I mean the whole outfit's pretty badass...???," she captioned the snap of her hilarious mismatched outfit.

WATCH: Katherine Heigl on Giving Birth to Son Joshua: 'I Actually Prefer the Adoption Way'

Heigel and her husband, musician Josh Kelley, welcomed baby Joshua on Dec. 20 -- and have shared tons of adorable pics of the newborn since. 

In fact, Kelley celebrated his 37th birthday last week with tons of baby "snuggles."

"How @joshbkelley is finishing off his birthday, with sleepy snuggles from his namesake! Could not be more grateful for this extraordinary man and for this extraordinary day that he was born!" Heigl sweetly captioned a sleepy snap of the two.

See more in the video below.