How to do: 3/4 Sit-Up

Step-by-step instructions

1. 1Lie down on the floor and secure your feet. Your legs should be bent at the knees.
2. 2Place your hands behind or to the side of your head. You will begin with your back on the ground. This will be your starting position.
3. 3Flex your hips and spine to raise your torso toward your knees.
4. 4At the top of the contraction your torso should be perpendicular to the ground. Reverse the motion, going only ¾ of the way down.
5. 5Repeat for the recommended amount of repetitions.

Photos & base instructions from the open-source Free Exercise DB (public domain).