Think about it: If you're doing crunches on the floor, you can only go so far back. Using an ab machine, such as a decline bench or exercise ball (no, that may not seem like a 'machine' but more ...

Crunches No ab workout is complete without crunches ... Cable crunch The cable crunch does require access to a gym and cable machine, but it's an excellent exercise that does well to target ...

By engaging your lower abs, reverse crunches help strengthen and tone ... fitness levels since they don’t require heavy weights or machines, Cardiello says. In addition to building strength ...