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

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.

1. You rocked out on the elliptical sans resistance. "WEEE," said everyone who ever went to town on the elliptical without any resistance. Fun? Yes. Effective? Nope.