Leighton Meester Works Up A Sweat [PHOTOS]

Gossip Girl’s Leighton Meester was spotted taking her puppy for a hike in Los Angeles yesterday (April 18). The actress looked as if she was working up a good sweat while donning the appropriate hiking gear – t-shirt, sweat pants and a bottle of water.

Meester has to stay in shape to look her best for the upcoming promotional tour for her film Monte Carlo which co-stars Katie Cassidy and Selena Gomez.

PHOTOS: Leighton Meester Plays Dress Up

The film is about three friends, played by the mentioned actresses, who pool their savings for a dream trip to Paris, which turns out to be a big disaster. When they decide to take a break from their lousy tour and sneak into the lobby of a five-star hotel, one of the girls is mistaken for a spoiled British heiress.

Before they get the chance to reveal their true identities, the girls are wrapped up in a whirlwind of paparazzi, haute couture, and romance in Monte Carlo, Monaco. The film is in theaters on July 1!

Watch the trailer …