Reese Witherspoon gym workout sunglasses blonde burn 60

Reese Witherspoon is getting toned! Looking happy as can be, the Oscar winner left her favorite gym, Burn 60, after working out with friends in Brentwood, Calif., on Thursday.

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

Outfitted in a black hoodie, leggings and colorful Asics, the sweaty star looked like she had a great time with friends kicking her butt into high gear. The 37-year-old has become 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.