Set-up: You'll 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 foot onto the second. keep the other leg off the floor and off the bench.
Lift: Keeping your arms straight, press your hips up and curl your body towards your foot as far as you can. Your knee should reach at least 90 degrees of flexion.
Repetitions: Perform all prescribed reps on one side, then on the other. This counts as one set.