Hang from a high bar with your hands shoulder-with apart, your arms fully extended, and your legs hanging straight down.
Straighten your lower back by tilting your pelvis backward.
Execution
Keeping your knees straight, slowly raise your legs as high as possible by flexing your hips and your abdomen. Don’t forget to exhale.
Hold for a count of two.
Inhale as you slowly lower your legs to the starting position.
Repeat for the desired number of repetitions.
Comments and tips
Keep your lower back as straight as possible. Ideally, the frame from which you hang should have padding to support your lower back (see video). You should keep your lower back pressed against the padding. If such a frame is unavailable, use a captain’s chair.
Your abs and obliques will contract dynamically only if you flex your abdomen. If you do not flex your abdomen, your abs and obliques will only act as stabilizers.
Do not swing your legs or use momentum to raise them.
To add resistance and make the exercise more difficult, pull a cable with your feet.
Use wrist or elbow straps for extra support.
The hanging straight leg and hip raise is essentially the same exercise as the captain’s chair leg and hip raise, an exercise that, in one classic study, was found to be the most effective for your obliques and the second most effective for your abs.