just sprung for an expensive ab exerciser...i noticed that crunches and sit-ups were making my abs protrude instead of tightening them....maybe cause i`m getting older...
bought an "ab-coaster".......and i gotta say,it`s some serious shit....doesn`t put strain on your back(even though that even feels tighter and stronger) and tightens your core like a m.f.`er....abs and obliques...
downside...it is expensive($399) for one body part...but,who wants a f-cked up,flabby waist line?....
believe me...it works..
I've got the "Body by Jake" ab and back plus and a tubular ab worker that you use on the floor. I alternate 50 reps between the two. Once I work past the initial few days of soreness I can bump my total reps way up. I can feel the difference just in a few days.