3.5 months after giving birth, Samantha Busch shows off physique

INDIANAPOLIS, IN - JULY 25: Kyle Busch, driver of the #54 Monster Energy Toyota, is assisted by his wife Samantha as he tries to cool off following the NASCAR XFINITY Series Lilly Diabetes 250 at Indianapolis Motor Speedway on July 25, 2015 in Indianapolis, Indiana. (Photo by Brian Lawdermilk/Getty Images)

A self-described "fitness nut," Samantha Busch is well known among friends and followers for her proclivity for staying in absolutely top-notch physical shape.

From the looks of her latest Instagram photo, the wife of Sprint Cup Series driver Kyle Busch is having no trouble sticking to her mantra -- just three-and-a-half months removed from giving birth to the couple's first child, son Brexton.

In fact, if Kyle and Samantha ever engage in an arm-wrestling contest, Kyle would probably be well-served to bring his "A" Game.