Reese Witherspoon blonde hat spandex gym workout

Reese Witherspoon has been hitting the gym hard as of recently. The mom of three was seen leaving Burn 60 in Brentwood, Calif., on Monday after an intense work out.

According to their website, Burn 60 is a "fun, effective, fast-paced, 60-minute workout for all fitness levels." Whatever the workout is -- Reese has never looked better!

For the workout, the 37-year-old wore cropped leggings, a black tank top, a baseball hat and was carrying a monogramed Goyard St. Louis tote bag.

Over the summer, the Oscar winner became quite the gym rat, and recently debuted her slimmer figure at the Devil's Knot premiere during the Toronto International FIlm Festival.

Devil's Knot, which hits theaters later this year, is based on the true story of three teenagers who were falsely convicted of killing two 8-year-old boys in Tennessee. The trio, known as the West Memphis 3, were released two years ago after spending 18 years behind bars. Reese plays Pam Hobbs, the mother of victim Stevie Branch, and Colin Firth also stars in the movie as Ronald Lax, a private investigator who represented one of the accused teens.