Sounds like you never fasted before..If so you will find it very hard to weight train, as you will be too weak..A little light cadrio, but fasting is a time for resting and letting the body rest and detox..Lots of exercise puts a lot of stress on the body and makes acid that the body must now remove..
Drinking protien shakes will not let your digestion system shut down and you will not be fasting..Some fruit or veggie juice is ok..
Get yourself a book on the correct way to get the most out of fasting..