9 Rookie Mistakes You Can't Believe You Used to Make at the Gym.(5)

http://www.womenshealthmag.com/fitness/workout-mistakes-you-used-to-make-all-the-time

It's a miracle you made it out in one piece back then.

5. You did crunches on crunches on crunches. Six-pack abs like Britney's are only millions and millions of crunches away—so you thought. (Here's a way more effective abs workout.)