How ever many you can do. Typically, in one rep you will go until you reach exhaustion, meaning you physically can't do anymore. Also if your sit-ups become sloppy and you lose proper technique, you are no longer doing as much good as you would doing the proper technique. So as soon as you are physically unable to do anymore proper sit-ups, then you have done one rep. If you plan on doing more reps you can follow the same guidlines, but basically one rep is not one set number, but instead it is just as many as you can do.
800
i can do 100 but it is depending on how fit you are
15
The fixator is one of many muscles used during situps. The fixator muscle stabilizes one part of your body when you move another part.
500
A sit up or curl up test measures the muscular strength and endurance of the abdominals and hip-flexors. Do as many sit ups in one minute.
No one really knows how many sit-ups Terrell Owens does in a day. It is, however, known that he will probably not make another NFL team. His abs are strong, but his legs are old.
you will lose on average 150 calories doing 230 sit ups.
Jackie Chan does sit ups in several movies, but perhaps the one you are thinking of is "Wheels on Meals" where he and Yuen Biao do sit ups together right at the beginning of the movie.
about a million
by excersing like sit ups push ups 25% or belly ups
you should do 3000... 1000 is one pound..