Popsugar Health & Fitness Gif Workouts At-Home Cardio HIIT Workout Full-Body Fitness Quickie: 20-Minute Cardio HIIT Workout 18 June 2018 by Susi May View On One Page Photo 1 of 9 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 1 Warmup: Knees and Toes Start with two high knees, bringing your right knee to your left hand, then your left knee to your right hand. Now rotate your right knee slightly outward to bring your right ankle to your left hand, then your left ankle to your right hand. Continue in this alternating pattern for 30 seconds, then head to the floor for plank jacks. Previous Next Start Slideshow GIF Workouts20-Minute WorkoutsBodyweight WorkoutsIntermediate WorkoutsHIITFull-Body WorkoutsCardio WorkoutsStrength TrainingWorkoutsGif