This new workout is solid.

The back is the new core.

But don't take our word for it. Matthew McConaughey, Rob Lowe, Lance Armstrong and pro surfer Kelly Slater all swear by a workout called Foundation. Developed by Dr. Eric Goodman and Lance Armstrong's trainer Peter Park (pictured), the exercises shift the focus from the front of your body to the back to strengthen your middle in a whole new way.

Until now, only people in California or Colorado could take Foundation classes. But with the recent release of the book Foundation: Redefine Your Core, Conquer Back Pain, and Move with Confidence, anyone can train like a celeb. You get three step-by-step workouts of increasing intensity to ease back pain, improve your posture (to instantly look thinner) and correct your alignment so you can exercise more effectively.

Watch a video demo of Foundation's signature move here.  

Buy the book here. 

It's got your back.

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