Hang from a high bar with your hands shoulder-with apart, your arms fully extended, and your legs straight.
Straighten your lower back by tilting your pelvis backward.
Exhale as you slowly raise your knees as high as possible by flexing your hips and your abdomen.
Hold for a count of two.
Inhale as you slowly lower your legs to the starting position.
Comments and tips
Make sure that you’re not just raising your knees. After raising your knees, you must also flex your abdomen to raise your knees even higher. If you do not flex your abdomen, your abs and obliques will only function as stabilizers.
Do not swing or use momentum.
Keep your lower back as straight as possible throughout the exercise. The exercise is best performed with your lower back pressed against a padded surface for support (see video). Instead of hanging from a bar with an unsupported lower back, use a captain’s chair if one is available.
The hanging leg and hip raise is essentially the same as the captain’s chair leg and hip raise, an exercise that, in one classic study, was found to be the most effective at activating the obliques and the second most effective at activating the abs.