Start standing with your feet hip-width apart and your toes pointing out slightly, holding a kettlebell with both hands by the handle. Let your arms rest so the kettlebell hangs down between your legs.
Keep your back flat, your chest up, and brace your core. Hinge (bend) at your hips, shifting your glutes backward and slightly bend at your knees.
Drive your feet into the ground and squeeze your quads and glutes as you explosively snap your hips forward, coming into a standing position. The swing should come from the momentum of the hips, not your arms.
Be sure to maintain a relaxed grip on the kettlebell, letting the force from your hips carry the kettlebell up instead of pulling it with your arms.
As soon as the kettlebell reaches its peak height and you're standing upright with your legs straight, let it swing back down as you hinge at your hips and bend your knee, returning to the starting position.
Repeat for 30 seconds, then take 20 seconds of rest.