Popsugar Health & Fitness 15-Minute Workouts 30-Day Fitness Challenge Crush Your 2019 Fitness Goals With This 30-Day Total-Body Challenge 6 January 2019 by Jenny Sugar View On One Page Photo 8 of 24 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 8 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 15-Minute WorkoutsBeginner WorkoutsFitness ChallengesStrength TrainingWorkouts