How would fasting and exercise effect metabolism?

So...I've been on a diet for a while and lost over 50 pounds, but this past week I've been off my diet and eating all kinds of stuff because it has been graduation week (I'm finally a High School graduate) and everyone has been saying It's a time for...

celebration. They were right, right? Anyway, starting Monday, I'm thinking about going on a fast and not eating anything but drinking water and going to the gym. My question is, and sorry if it's a little confusing, if I fast and exercise what kind of effect would that have on my metabolism? Would it slow down, stay the same, or improve (which is what I want)? I know fasting slows it down and exercise speeds it up, so what would happen if you add the two? Again, sorry if it's confusing, I need to get back on track. I want to look good going to college!
Thanks!!

your metabolism would go faster, and you would need more food, fasting isnt a good idea because not eating and exercising can make you weary and weak
a healthy diet (fruits, veggy, etc.) and exercise would be better

During a fast you do not exercise a lot because you are drained of your massive calorie intake. Plus during a fast you can drink juice and things because you are still suppose to get the right amount of vitamins everyday as usual. If you just drink water that is called starving not fasting. Get your facts and do research before jumping into that black hole you call a 'great idea'.