Another beneficial strengthening exercise for the lower back and glutes.
Lie on your back with knees bent. Place your feet flat on the floor about hip-width apart (heels should be a few inches away from your buttocks). Press your arms into the floor for support and brace your core to minimize the arch in your lower back.
From here, push through your heels and squeeze your glutes to lift your hips up until your body forms a straight line from your knees to your shoulders. As you get stronger, focus on getting your shins as close to vertical as you comfortably can at the top of the movement. Pause, then slowly lower your hips to return to starting position. Do 8 to 10 reps total.