The hip raise with knee squeeze is a basic bodyweight exercise that increases strength in the glutes in addition to the hamstrings and lower back.
Lie on your back with your knees bent and heels flat against the floor. Keep your feet hip-width apart. Place a medicine ball between your knees.
Tighten your abs and press your heels into the floor, drive your hips upward, and squeeze your knees together. Finish the movement by squeezing your glutes, making sure to not use your lower back, and return to starting position.
Squeeze your glutes at the top of the movement for a full contraction.
Apply pressure to the ball between your knees at all points throughout the movement.
Your weight and force should be generated through your heels. Avoid pressing through your toes.