I was searching the internet for some good mass building workout. Most workout plans I have come across suggested a 3 day workout plan, focusing on 2 body parts per workout day. When i searched and found a couple of pro body builders workout plans, they focused on working each body part twice a week. Why is this? from what i was told if you work each body part twice a week, that is considered over training and can lead to decreases in size. Is this because of all the supplements there taking they can recover quicker. One reason i ask is because in the winter I have some more free time, and would like to hit the gym more often, but i don't want to over train either.