Sit-Ups

Sit on an abdominal board and place your feet under the pads or sit on the floor with your feet under an immovable object.
 
Lie back onto the board or floor with your arms across your chest or hands behind your head.
 
Curl your upper body up until it is at angle slightly less than 90 degrees to the floor; return to the starting position.
 
The entire motion should be done in a smooth, controlled manner that lasts about 3 seconds, with the downward movement no faster than the upward.