Hello there. Five days into water fast.

Hello, I am five days of fifty into my Water Fast and I am absolutely exhausted! I decided to take the stairs five floors to my apartment, and get some exercise. Upon reflection I realized this was not a wise decision at all. I almost passed out along the way. I have fasted a couple of times before, but the longest I have made it is five days. Fortunately this time I am not the least bit hungry. No overwhelming impulses to mow the kitchen down, tasting anything and everything. If one were watching me they'd probably think I were on drugs. I think I have the right mindset to succeed this time. I am wondering whether my body will become used to going without food and my energy will pick up. I can't see it being a pleasant experience otherwise, no matter how spiritually committed I am. Namaste, and best regards.