Jennifer Lopez's Celebrity Trainer Tracy Anderson Reveals J.Lo's Workout and Diet Secrets

It's hard to beieve that Jennifer Lopez is 44. But some say that 40 is the new 20, and J.Lo certainly lives up to this with her rock hard bod. Her personal trainer tells Allure magazine how she whips J.Lo's body into shape.

American multi-platform fitness entrepreneur and author Tracy Anderson is best known for her Tracy Anderson Method that she uses on clients including Madonna, Gwyneth Paltrow and Shakira.

With Jennifer "I keep her butt toned and in position. We do planks, moving the legs and butt at different angles," said Anderson.

It's not only important to keep this mega stars famous booty in shape, but her entire body as well. Being in the spotlight 24/7 and being a full-time mommy makes it essential for Lopez to stay in sublime shape.

"She does my method, which includes muscular structure work and between nine and 13 different exercises that change every 10 days, and dance aerobics as well," explains Anderson.

Anderson says that one of her favorite qualities about Lopez is her youthful spirit, which she believes is a huge part in staying fit.

"Every time I see her, I'm thinking, 'Really?' She's so youthful inside, it just penetrates to the outside."

Jennifer Lopez is a mega threat when it comes to the entertainment industry. She is an actress, author, fashion designer, dancer, producer and singer. She gained her first job as a Fly Girl dancer on In Living Color in 1991. Twenty years later this Fly Girl has released eight studio albums, followed by a ten-year career in dance and acting.

For a glance at this star's stunning figure check out the teaser from her music new video, "Booty" with rapper Iggy Azalea.