Popsugar Fitness Workouts 20-Minute Cardio HIIT Workout Boost Your Metabolism With This At-Home HIIT Workout December 29, 2017 by Susi May View On One Page Photo 3 of 4 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 3 Lunge Skip Come into a lunge with your right leg back. Swing your right leg forward to hop up on your left foot, and land softly back in a lunge. Repeat for 40 seconds, then rest for 20. Remember: You will need to alternate legs; on second and fourth sets, step back with your left leg. Previous Next Start Slideshow WorkoutsStrength TrainingAdvanced WorkoutsBodyweight WorkoutsGIFHIIT WorkoutsIntermediate WorkoutsFull-Body Workouts20-Minute Workouts