Jennifer Aniston traded her teeny bikini for equally ab-baring workout gear in Cabo yesterday. Courteney Cox was a bit more covered up for her exercise, while Cougar Town's newest guest star Sheryl Crow sat out the fitness portion of the vacation entirely - instead opting to stay in her bathing suit and lounge by the pool. The trio are in Mexico ahead of Aniston's 41st birthday on Thursday, but it's not a girls trip by any means. David Arquette of course came along and Jennifer's sexy Golden Globes date and costar Gerard Butler is also there! Whether any romance rumors are true or if it's just a friendly trip, Aniston looks like she is having a blast surrounded by people she loves in one of her favorite spots.

To see lots more of Jennifer and Courteney in their workout gear just read more.