I'm a 33 year old male. Because of my work schedule, I can work out only two days in a row, then rest for two days. Generally I drink about 64oz of water on the days I do weights or cardio. The days I work, I usually drink a little less. I don't want to gain a bunch of water weight, but I want to stay hydrated. Is their an amount of water that I need to drink on workout days opposed to resting days? Or is 64oz a good rule of thumb to stick too.