This article originally appeared in Shape.
If you look up HIIT (high-intensity interval training) in the dictionary, you'll be surprised to see Kayla Itsines' face is not there on the page, basically staring at you asking why you aren't doing mountain climbers right now.
Jokes aside, Itsines has built a reputation for being the queen of bodyweight HIIT workouts — though her fitness empire and workout programs have certainly expanded throughout to years — and that's because they work.
HIIT (whether from Itsines or otherwise) asks for maximal effort with minimal rest, but the concept is meant to be efficient so you aren't left drained but rather energized and feeling like you got an insanely good workout in half the time of your usual moderate-intensity routine. (Related: This Full-Body HIIT Workout for Beginners Will Leave You Dripping In Sweat)
This HIIT cardio workout from Itsines is a total-body routine that will work to strengthen your quads, glutes, hamstrings, chest, arms, shoulders, and core while also improving your stability and muscular endurance. See, efficient! Complete each exercise in order, quickly transitioning between exercises to keep your heart rate elevated throughout.