The Horrible Bosses actress was voted as the star who most inspires people to work out, as well as the best fitness buddy, according to Contactmusic.
Other stars who made the top five were Halle Berry, Sofia Vergara, Cameron Diaz and Blake Lively.
Jennifer Hudson was also voted in as the 'Best Diet Spokesperson Transformation'. Hudson's new Weight Watchers advertisement was just released, in which she is seen singing a duet with herself.
Britney Spears won the 'Best Career Makeover/Comeback' category and Kate Middleton has the 'Best Celeb Wardrobe'.
Earlier this month, Aniston beat sex symbol Marilyn Monroe as the 'Hottest Woman of All Time' in a Men's Health poll.
Aniston recently admitted that she decided to cut her locks due to the extensions damaging her hair.
Watch Jennifer Hudson's Weight Watchers advertisement below: