We're booty building with today's HIIT stair circuit. Using my favorite squat variations we're going to hit all 3 sections (lower, mid & upper) of your glutes. Why? So you can have a firm, round and lifted booty. Drink plenty of water, rest as needed and remember to complete a single set of each exercise, then repeat the circuit for a total of 3 rounds. Rest as needed between rounds, but no longer than 2 minutes.