While believing in most of the myths above won't actually hurt you (just stop you from getting in quality workouts), the last one could be detrimental to your health:
I don't want to retain water so I don't drink: Amazingly there are still some people who believe this. But the way the body works, quite the opposite is true. If you only give it small amounts of water it will store as much as it can - it doesn't know when you'll next give it more. If, however, you drink water regularly, your body will happily release lots of water. You'll feel less bloated, get fewer headaches, and be healthier all round.
So how well did you score?
Whether they cause you to waste your money, waste your workout time, or even follow unhealthy practices, exercises myths are worth revealing and understanding.