Popsugar Health & Fitness 15-Minute Workouts Quick Home Workout Think You Can't Get in a Good Workout in 15 Minutes? This Workout Will Prove You Wrong 1 December 2018 by Jenny Sugar View On One Page Photo 9 of 15 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 9 High Knees Run in place while lifting your knees high to the level of your waist. Engage your abs as your knee comes up. Pump your arms to warm up your upper body. Do high knees for 45 seconds. Rest for 15 seconds. Previous Next Start Slideshow 15-Minute WorkoutsBodyweight ExercisesIntermediate WorkoutsCardio WorkoutsWorkouts