I have had some similar experiences. I always feel more energized after the first 4 days of my fasts and I only sleep around 6-7 hours and feel like I could run a marathon. I am kind of in love with all the extra energy I have and how light I feel during. I would just like to caution you maybe about doing everything you feel capable of. You may be capable, but you want this time to re-cooperate your body not to exhaust it to the end of it's resources. It's a hard battle to fight when you feel so light and energized and free...so good luck to you.
I think a lot of it has to do with our bodies not being weighed down by the process of digestion as when we are eating.
Great job on making it 14 days!!! Hope all goes well.
How long are you shooting for?? Or do you have a specific goal in mind??