Instead of just doing abs laying down with a weight on my floor doing like 80 of those every 2 or three days i am going to the gym and lying on the bench thing that lays toward the ground and you lay all the way back and put your feet up between two paddings to keep you there. I use a 5kg weight on my chest and do about as many as i can. Does any one know if this is better then doing like 80 sit ups because i am really getting tired and over doing tons of sit ups i prefer reps like 8-12. Well basically what i am asking is there any way to get a good workout in your abs where you don't have to do a 80+ reps which is how long it take for me to get tired and also how often should i work abs ?