How often should i do crunches?

As often as you feel!
I do them every other day during my workout

I do them with the SHRED! Or some form of them...

I also use to do some ball exercises that involved them. They are really effective if you stick with them and do them right!

K thanks yall : )

I would only do crunches if you include them in a more holistic ab routine. Crunches are not the best workout for the abs. Useful article: http://www.newsweek.com/blogs/the-hu...on-t-work.html

Planks, pushups, and lifting (specifically squats) are generally considered more ergonomic and productive exercises for the core. (Remember, don't JUST focus on the abs, focus on the whole core- which includes the lower back, obliques, spinal strength, etc).

good luck!