Popsugar Health & Fitness Workouts How to Strengthen Your Abs Get Rock-Solid Abs With These 15 Strengthening and Toning Exercises 28 August 2018 by Tamara Pridgett View On One Page Photo 2 of 15 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 2 High Knees Hold your hands at waist level. Hop the right knee up toward your hands, then quickly switch legs and hop the left knee up. This counts as one rep. Previous Next Start Slideshow Trainer TipsBodyweight ExercisesCore ExercisesStrength TrainingWorkoutsAb Exercises