Not sure if I can post a response to a post but it is a very deep subject with too much to respond to in a forum so I am doing it here.
This is my opinion in response to a member who asked this question below.

1) How does AAS work? The reason we are able to eat so much and grow so fast is because very quick protein synthesis and nitrogen retention. This is more or less higher conversion/transcription rates of protein to feed muscle growth and cellular repair. So 4000 calories a day is fine if your lifting and eating to grow because your are on a substance that aids in the conversion of protein to muscle. Now consider if you were/are a "couch potato", and you eat 4000 a day you will get fat quick on AAS or not. Lets assume we are all natural for the moment. 4000/day couch potato = Fat, 4000/day lifting weights = moderate strength gains some mass and a little fat, 4000/day and running three triathlons a week = exhaustion and collapse. See my point. The question to start with is; how much do you eat before cycle lifting 5 times a week and what do you need to consume to gain off cycle. A lot of hw here on what works for your body and what a "clean" diet is. Next question is, how much more can you eat while on a cycle and what are the reasonable lean muscle gains you can expect? To answer that requires research on your part and realistic views on your expectations. I love seeing people who are happy to report that they have gained ten lbs in two weeks on Test,Dbol and Deca but show no pictures or diet plan to show what kind of gains they have made. If they are trying to gain 8 lbs of water and 2 lbs of muscle then they have proper claim as they have achieved just that. What I am saying here is Lean Muscle gains is the goal not just mass! Would you rather be a pound of feathers or a pound of lead here? Also by realistic I mean what can you keep as in what is an acceptable loss as well. If you believe you will keep 100% of your gains totally off gear you are mistaken and need to evaluate your goals.

Diet is key but lets define what a "clean" diet is for YOU. I am not saying what your diet should be. What I am saying is there are several different views on a clean diet. If clean for you is Whole milk, natural butter, steaks and chicken with seasoning and spices but grilled, and potatoes with fat free sour cream and salt and pepper with butter and chives, big pancake breakfast with whole grain oats and sugar free syrup with coffee and fat free creamer and then 4 protein shakes a day with weight gain; THEN you will get big! On cycle you will get stronger and bigger and swollen like a tic from sodium and you will put on fat. Yet by some standards because there is no hydrogenated or transfats in your plan and fat free products and natural grains and vegetables and all your meats are grilled or baked this qualifies as a clean diet plan. Off cycle if you ate like this every day you would get fat quick and would have to increase your cardio a ton just to stay down in weight. On the other hand if you eat your meats grilled with little to no salts, baked potatoes with nothing but Greek yogurt or plain, your breakfast consisted of nuts fruits whole grain toast with a scoop of protein in your coffee instead of creamer and egg whites instead of pancakes and 3-4 small meals consisting of protein bars and nuts and vegetable in between your main meals every day then you have a different definition of clean. The key here is to be totally honest with yourself and what you eat. This is actually very hard to do because it is so much more food than the first diet plan I described and is expensive as shit. Watch this video clip of Jay Cutler shopping at costco for one weeks worth of groceries. http://www.youtube.com/watch?v=A9TnXNP8JSU
Also think about the fact that you are not always on gear and so what happens to your body when you consume all that food with a slower protein synthesis. Your body may react differently then other people naturally and you will actually put on fat instead of muscle unless you balance caloric intake with caloric burn off. Increased cardio here.

2) Now lets talk about PCT. There really is no excuse for a poor PCT especially with a resource like this available to you. But it doesn't have to be the only resource you have. Try to get your hands on medical journals like The Journal of Endocrinology and Metabolism and The New England Journal of Medicine to find medical studies of different medicines in different case studies. I have found tons on HCG for HPTA supression from intentionally induced to natural, both testosterone and latent growth in prepubescent boys and in TRT in older men. In short these studies show that HCG does impact the HPTA and is very useful. http://jcem.endojournals.org/search?fulltext=HCG+testicular+atrophy+&sub....
The reason PCT is critical is because your trying to recover from a state of non-homeostasis. Your body is trying to increase it's own natural hormone production and return to natural balance. In order to do this your first reaction is to produce cortisol quickly to cope with the stress on your system and this causes whats called a catabolic state. Your body's natural reaction is to actually shrink as fast as possible. In order to combat this we have to trick our HPTA into full production as fast as possible while at the same time not produce too much estrogen so as to cause other problems in other departments. To do this I believe you need all three products. HCG, Nolva and Clomid, these hit the important parts of recovery, LH, Testicular re-sensitization and rebound gyno. This is a very technical and vast topic and I would get my hands on as much of it as I can if I were you so you understand why you are taking these meds and for what purpose. Again this is also a little controversial because there are varying opinions on the use of HCG in a cycle and in PCT. My personal experience is I won't do a cycle without it.

So it really boils down to the same two things everyone else is going to tell you, Diet and PCT! Routine goes without say but I would say more important then these two factors would be research brother.