Popsugar Health & Fitness Workouts What Are the Best Ab Exercises? These Are the 40 Most Effective Ab Exercises to Sculpt Your 6-Pack 20 June 2018 by Jenny Sugar View On One Page Photo 26 of 41 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 26 Runner's Crunch Start on your back with your elbows resting on the floor at a 90-degree angle. With your core engaged, roll up to almost sitting while bringing your right knee up to meet your left elbow. It should feel a little like running. With control, straighten your leg as you slowly lean your back down, vertebra by vertebra, until your shoulders touch the mat last. Alternate with your other leg to complete one rep. Previous Next Start Slideshow WorkoutsAb Exercises