Set up with a kettlebell between your feet (handle in line with your shoe laces), feet shoulder width apart. Push your hips back, keeping the legs close to straight, with unlocked/soft knees. Holding the bell, squeeze your glutes and quads (front of thigh) to drive the hips forward. Push the hips back to the start position to lower the bell. Keep the bell close to you, moving up and down in a straight line.

Hamstrings

Hinge