Hmmm, not sure I can add anything here, the boys seem to have done a very fine job of explaining the situation.
here’s a quote from Bill Roberts on the matter[quote]
The two-week cycles do give really fast recovery. It’s not that there is no HPTA shutdown, as there is during the two weeks, but the pituitary is immediately ready to respond to LHRH instead of so to speak having to be awakened from sleep (in more precise speaking, having greatly lowered LHRH responsiveness), and the testes are also immediately ready to respond to LH.
While if HCG is used in for example an 8 week cycle then the testes also are able to respond well to LH immediately, there’s nothing that in like manner avoid reduced responsiveness of the pituitary. [/quote]
So it’s not just a matter of shutdown, it’s a matter of being primed to come back online. LH sensitivity is still very high 2 weeks into a cycle, which means any increase in LH will generate a large response from the body in terms of recovery. As cycles go on in length LH sensitivity drops off rapidly. In fact, it drops off fairly rapidly after the 14 day mark. That means past this point the testes are NOT primed to start producing their own test (unless using HCG), but more important is the pituitary–HCG can’t help that suppression in the way it does the testes, and it takes a dive.
In longer cycles these sensitivities to the body’s own “ignition button” are at rock bottom, at that makes recovery difficult. To continue the car analogy, it’s like not just shutting off the car (testes), but draining the gas tank and oil completely. Remember, the HPTA is an axis of 3 different glands, not just testes. It is testes, pituitary, and hypothalamus. These glands work in concert much of the time, but they can also react in different ways to different stimuli, and that includes recovery.
The reason 12 weeks is typically picked as a starting point is because the point of diminishing returns occurs around this point. Often earlier, but 12 weeks generally ensures that one will milk all the benefit from exogenous hormones that is possible, with not too much wasted time. Bill Roberts has said before that a cycle is longer than efficient if there is a lot of time spent with exogenous hormones PAST the point of diminishing returns with muscle gain/strength. In other words, you’re wasting gear. You should simply come off at this point. 16 weeks is for the most part pretty well past this point.
Stop now, it’s the easiest thing to do and it will waste very little gear compared to going on and possibly re-injuring the ankle in an accident. I would spend a total of 4 weeks off at least to ensure recovery (cyp has a longer halflife than most used for 2 week cycles and will still be hanging around in his system past 14 days even if he doesn’t take another shot today) if he’s going to go on for 12 weeks afterwards.