Soldato
Most of it is common sense:
- if you have small amount* of protein pre-training, then you want a bigger bolus within a couple of hours after. There's no need to slam a shake the exact moment training finishes though.
- if you have a larger amount of protein** pre-training, then you can get away with a smaller bolus because the first will still be digesting
- if you're doing anything strenuous (like lifting weights or your cycling hammers your legs), then it's probably a good idea to consume some protein before. For anything low intensity going fasted is fine.
*there is something of a minimum effective dose with protein due to something called the leucine threshhold, so somewhere between 20-40g of high quality protein per meal is enough to hit this
** i.e. a meal, although obviously some activities are not so fun when your belly is pretty full
Danny Lennon from Sigma Nutrition did a good basic write-up on protein here which is worth reading. The only thing I'd add is that if you're dieting, you're not in a physiological position to maximise muscle gain like you are when you're ingesting sufficient calories, and so distribution (outside of protein around the training window) becomes less important.
(I have no idea what the last sentence means...)