Popsugar Health & Fitness Fast Fitness 10-Minute Cardio For Abs Carve Your Core With 10 Minutes of Cardio 15 November 2018 by Susi May View On One Page Photo 1 of 10 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 1 High Knee Run This cardio move is great for runners; it not only works the lower fibres of the abs, but it helps train for quick turnover in gait to increase speed. Run in place while lifting your knees high to the level of your waist. Engage your abs as the knee comes up. Pump your arms to warm up your upper body. Keep running with high knees for 30 seconds. Previous Next Start Slideshow Fast FitnessFast Fitness WorkoutsBodyweight ExercisesBodyweight WorkoutsIntermediate WorkoutsAb Workouts10-Minute WorkoutsStrength TrainingWorkouts