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Just because the fall is finally here, it doesn't mean Reese Witherspoon is slowing down on her summer workout regime! On Tuesday, the Sweet Home Alabama star was once again spotted at the gym toning up her recently slimmed-down figure.

We gotta hand it to Reese -- she really seems to be dedicated to working out! The petite blonde was photographed wearing cropped black leggins, a sweatshirt, colorful Asics and pulled her hair back with a headband. The mom of three has been hitting Burn 60 in Brentwood on the reg for the past few months. We aren't sure if it's because she is exercising for a role in one of her upcoming films, or if she just got inspired after pics of her butt were splashed all over the Internet when photogs caught the Oscar winner accidentally flashing her backside in June. Maybe that's just what the star needed to kick her butt into gear!

The 37-year-old made headlines when she debuted her slimmer bod at the Devil's Knot premiere during the Toronto International Film Festival earlier this month.

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.