Yeah its a good idea to wean into it! That's what I did. I juiced for today and now (after midnight) I am full water until aug 7th! (: I dont think I will be doing too much physical activity during my fast. One time while I was doing a fast I had Incorporated exercise into it right from the start and didnt feel great, maybe I just pushed myself too hard though lol. So yeah this time I will be taking it a tad easier haha! Great luck with your fast as well!! (: