The book, written by Aniston's long-time friend and trainer Mandy Ingber, is a 28-day program that combines yoga and toning exercises, ABC News reported.
“It’s yoga paired with toning exercises, so people who were bored with yoga might try it, or people that were really into yoga might get a little extra workout,” Ingber told ABC.
The "We're the Millers" star and Ingber reportedly practice the listed exercises about three times a week. According to Ingber, the "tree pose" is Aniston's favorite.
“She’s really good at it,” Ingber said. “It’s the ability to be able to find your sense of focus in the middle of a lot that’s going on. It runs right through the center of the body.”