“ An empty stomach triggers a cascade of hormonal changes throughout the body that are conducive to both building muscle and burning fat. ”

The fasted state produces two significant effects:

1. Improved insulin sensitivity.

2. The second reason a good old-fashioned fast can promote muscle gain and fat loss comes down to growth hormone (GH), a magical elixir of a hormone that helps the body make new muscle tissue, burn fat.

If you really want to Fast Before Exercise, you can try this action plan:

You can consume more than just water.
Break your fast whenever you'd like.
Eat as many meals as you'd like.

I on the contrary workout better while my stomach is full. As far as my study is concerned, I found most of the people feel weak working-out on an empty stomach.
I had read somewhere that fasting before exercise helps you grow up, conversely I am also one of those who eat at least a bit before working-out. Lol

I have heard its best to exercise on an empty stomache also
 

My workout of choice is the elliptical machine to get my heart rate up for a while and I feel better when I jump on that thing not having eaten for a few hours prior.