rear decline bridge

Lie on your back with your feet flat on the ground and your knees bent. Place your arms by your sides with your palms facing down. Engage your glutes and hamstrings, and lift your hips off the ground until your body forms a straight line from your knees to your shoulders. Hold this position for a few seconds, then slowly lower your hips back down to the starting position. Repeat for the desired number of repetitions.