Matthew McConaughey's Abs!

Matthew McConaughey needed to gain flexibility, agility, and endurance for his role in 'Sahara.' His workout routine includes cardio, rope climbing and weight training. He hired celeb trainer Gunnar Peterson to whip him into shape using his famous "Core Secrets" workout. Nick Lachey and Brooke Burke also swear by Peterson's workout, which targets abdominals with a medicine ball.