NO NO NO to the pizza -
Here is a good site about post work ou food :)
What you should and should NOT eat after a workout.
Simply put, aside from water (which you should already know you need) your post workout meal needs to contain 2 things, and it needs to not contain 1. You should be eating protein and carbs. You should NOT be eating fat. More on the protein and carbs you need a little later. First, let's start with a quick explanation of why you shouldn't eat fat after a workout.
Many times throughout this website I explain why fat is NOT a bad thing (when it's the "good" fat) and why it is an important part of everyone's diet. However, there just happens to be a certain time when fat (good or bad) wouldn't be good to eat. This of course is in the post workout meal. Simply put, fat slows down digestion. In this case, it would be slowing down the digestion of protein and carbs. This, as you're about to find out, is the exact opposite of what you want to happen
I like to eat unsweetened applesauce and 16 oz of water after I work out. I also like to eat fat free yogurt if I haven't already eaten it for breakfast.