Set-up: You will need two supports for this exercise - the first one to hang from with your arms (for instance a bar in a smith machine rack, gymnastic rings, or a sturdy table), and the second to elevate your feet with (a simple bench or sturdy chair should suffice). Start by grasping the first to initiate a hang, then raising your feet onto the second.
Movement: Keeping your arms straight, press your hips up and curl your body towards your feet as far as you can. Your knees should reach at least 90 degrees of flexion.