Popsugar Fitness 1Six8 1Six8's 23-minute HIIT Workout This 23-Minute HIIT Workout Will Get You Trim and Make You Look Younger 3 April, 2017 by Linda Cochrane 3 Shares View On One Page Photo 13 of 13 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 13 Plank Jacks Like the motion of a jumping jack, jump your legs wide and then back together. Previous Next Start Slideshow 1Six8HIIT WorkoutsExerciseHIIT