“My workout buddy...mama's in @caliabycarrie and the big man is in his fire truck PJs...whatever works! #StayThePath PS, please excuse my yoga form...I don't do much yoga, but like to stretch...,” Underwood captioned the clip.
Together the pair do a variety of yoga moves including downward facing dog, the cobra, and child’s pose.
Underwood spoke to ET at the GRAMMYs in February where she opened up about her workout routine, noting that she often plans around Isaiah’s schedule.
"I do whatever I can and make time for it. Isaiah goes down for a nap, I've been in my workout clothes all day long, I'm there, I'm ready, I make it happen," she said at the time. "If it's 15 minutes, that's good. If it's an hour, that's great. It just happens when and how it happens."