Jennifer Aniston gives workout tips to Courteney Cox

London: Actress Courteney Cox says her former `Friends` co-star Jennifer Aniston gave her a workout tip that proved very effective. The 49-year-old actress once had a problem with selecting some workout machine, which Aniston solved for her, reported Contactmusic. "I did Pilates three times a week until recently, when I tripped and broke my fall with my bony little wrist. It meant I needed two operations and couldn`t exercise for about three months," Cox said. "Jen turned me on to used an elliptical trainer to work out with, so I now use that too," she added.