Supplement companies, not to mention all the 'broscience' parrots all over the internet will tell you that you MUST have your PWO nutrition exactly 59.122338 minutes after your workout or the magical 'window of opportunity' will suddenly close. It's a fact that muscle cells are more sensitive PWO, protein synthesis is increased, rate of nutrient uptake is increased, etc - but the fact is this does not decline after an hour, or two or three for that matter. In fact to the contrary, there are studies which indicate these physiological changes are more efficient several hours PWO, and start to decline many many hours later.
Fasting 3-4 hours PWO will only maximize the fat burning effects of your workout and PWO cardio.
HST = Hypertrophy Specific Training - google it, you'll find some good info. In a nutshell, it's designed as a 3x a week total body workout. You would pick an exercise for each bodypart (think mainly compound exercises) and find our 15 rep max, 10 rep max, and 5 rep max for each exercise. You would do a 2 week block of each rep range starting with the 15 range. However, you start lower than your max - in 5lbs (or so) decrements. So as an example, let's say my 15 rep max for bench press is 190lbs. My 2 week block for the 15 rep range would look something like:
Monday (week 1): 165lbs x 15
Wednesday (week 1): 170lbs x 15
Friday (week 1): 175lbs x 15
Monday (week 2): 180lbs x 15
Wednesday (week 2): 185lbs x 15
Friday (week 2): 190lbs x 15 (to failure)
You'd only be doing 2-3 working sets depending on the exercise. You will only go to failure (obviously) on your last day. You would do your next 2 weeks in the 10 rep range, and another 2 weeks in the 5 rep range. So as you can see, we're dealing with progressive overload, increasing total load, etc. There is also a deload period but I don't want to get TOO much into it here, read up on it.
Having said all of that - what I am doing is not quite what I described above. I am doing a modifed system which combines HST principles along with some advanced techniques (drop sets, negatives, static holds, etc).
My God!! But I assume you're doing an upper body/lower body split then, right? i.e. the upper body and lower body still only get worked 3x each per week, just seperately, correct? Please don't tell me you're doing a total body workout 6x a week!!