Starting Position: Stand with feet shoulder-width apart, arms folded across your chest or hands behind your head.
Squat: Lower into a squat position, keeping your back straight, chest up, and knees behind your toes.
Push through your heels to stand back up, while simultaneously lifting one knee high towards your chest.
Return and Repeat: Return your foot to the floor and immediately lower back into a squat. Repeat the motion, alternating the knee you lift after each squat.
Perform this exercise with proper form to minimize the risk of injury and maximize its effectiveness.