Crunches have long been the go-to exercise for a post-workout ab finisher. Not only are they simple to execute, but you can't deny the burn that comes after just a few reps. Still, as fatigue sets in, ...

View post: I Tried 75 Hard Seven Times Before Committing. It Helped Me Lose 70 Pounds and Lower My Blood Pressure Crunches target superficial abs but may strain the lower back with improper form.

Add Yahoo as a preferred source to see more of our stories on Google. "Unlike fast-paced crunch variations, toe taps train the core to stabilize while the legs move independently," says Nicole ...