i forgot to mention that unlike primitive man we are 'consciously' choosing not to eat, so the body/brain has an option. it knows there is no search for food going on so it moves into a meditative state which is beneficial to healing. this is the only thing you will have to counter during your studies. gentle exercise like lymphasizing (rebounding) might help re-energize when needed. but on each fast i found the books i'd planned to read never did get read. the mind just totally relaxed.