im on day two of my 14day water fast, and feeling very weak, however, when i did my 10day Water Fast in november, i managed to walk 18miles on day 3 of my fast, and walked 6miles daily up to day 5 for uni and getting to station etc. i think our bodies are meant to adapt to the no water, hence why doctor paul bragg was able to hike through death valley during his Water Fasts with relative ease when he was in his 80s etc, even though many college students were passing out!