Gwyneth Paltrow: Trainer Kicked My "Sagging Ass" Into Shape

Credit: Steve Granitz/WireImage.com

Gwyneth Paltrow is saying so long to sag!

In her latest GOOP newsletter, the actress, 37, sings the praises of celebrity trainer Tracy Anderson (who also works with Jennifer Aniston and Courteney Cox).

"She has kicked my formerly sagging ass into shape, and I will be forever grateful," Paltrow blogs.

She shares a video of the trainer's "little arm series," which she did every day while "preparing for Iron Man."

The lower arm exercises, she writes, work wonders, "especially for the batwing problem."

She even enlisted her "dedicated" pals -- including Kristin Davis, Donna Karan and Cox -- to rave about the Tracy Anderson Method.

"I heard about Tracy through friends who had seen fantastic results," the Cougar Town star, 45, writes. "I have seen amazing results that I never thought were possible. My butt has lifted, my arms are sculpted, and my skin is tight and actually clings to the muscle again."