In and out squats

Instructions

Adopt a hip-width stance with the feet naturally turned out, head facing forward.
Lower your butt to your knees' level, keeping the weight on your heels, as if you are sitting on a chair.
Move back up and make a small hop.
Land with your feet together, bending your knees.
Lower your butt like for the first squat.
Move back up and make a small hop.
Land by spreading your legs apart at shoulder-width, bending your knees, and repeat.

Muscles