sit-ups are an advanced abdominal exercise.  This exercise would be great for any sports which require explosion off of the ground or anybody looking to build or strengthen their abs. Lie a few feet in front of a low cable free motion set up. Grab the cables which are set at a light weight anchor your feet down. Perform a crunch or quarter-half sit-up and lower yourself back down without letting your shoulders touch (unless you are an athlete looking to build explosive power off of your back) and squeeze your abs the entire time until you’re done with the set. Remember if you are not less than 10% body fat you should not even be thinking of six pack abs. Trainer Michael Behnken, MS, CSCS