Lie supine (on your back) on a bench with your legs straight.
Grasp the sides of the bench by your head for stability.
Press your lower back against the bench so that it is supported.
Execution
Exhale as you slowly flex your knees and hips and bring your knees toward your chest.
Once your hips are fully flexed, curl your hips up off the bench by flexing your abdomen.
Try to hold the contracted position for a second.
Inhale as you slowly reverse the motions and return your legs to the starting position.
Repeat.
Comments and tips
Keep your lower back straight so that it peels up off the bench as you raise your hips and then rolls back down onto the bench as you reverse the motion.
Keep the motions slow and controlled. Do not use momentum.
Make the lying leg and hip raise exercise easier by keeping your knees bent (see first video) or performing it on a slightly declined bench.
Make it more difficult by straightening your legs (see second video) or performing it on an inclined bench. You can also pull a cable with your feet (see third video).
Your abs and obliques only work as stabilizers until you flex your abdomen. The muscles that flex your hips are your iliopsoas, tensor fasciae latae, pectineus, sartorius, and adductors.
