I don't personally think that you had to starve yourself of your protien etc the day before your flush, especially as you are body building. It is only (mainly) fat that we abstain from the day of the flush (although many say we should only eat salads and drink broths etc).
See what this flush is like and if it is unbearable for you - why not try just cutting all fats and oils out next time?
We are all different and it very often works for us in different ways.