SO much has been discussed that I'm trying to figure out where to start. Let me go back to the original question, which I think is this:
"What I'm wondering is how SOON can you cycle if your using a TRT dose to bridge between cycles?"
And adding to that, it seems one of your key concerns is whether or not you will hold on to whatever you gained by coming off for a period of time. The answer is different for everyone but there are things you can do to prevent actual muscle loss during this period. More on that later.
For now, let's talk about why you should have time in cruise mode. More so, lets also talk about the physiological things that demand that you take time off.
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We don't fully understand all of the things that take place in the body that makes things difficult in terms of building muscle mass indefinitely. But if I'm honest about it - we don't have to understand all of the mechanisms but only that it consistently rings true in ALL of us. It seems that having linear gains is almost impossible, if not just something we experience briefly, say 8-12 weeks at a time.
Sure, desensitization is a hypothesis as well as myostatin resistance. But there are other things too, namely, getting fat and increasing insulin resistance. These are the two main things I believe. - and not surprisingly, there is an activity that causes both of these to occur - caloric surplus. Consider your body more productive the leaner it gets and more inefficient the fatter it gets. True story, at least for myself. How do you think bodybuilders can hold on to so much mass while taking relatively low amounts of gear? Because they walk around at 5-10% BF year round!
Regardless, Ecclesiastes 3:1 tells us there is a time for everything under the sun:
"For everything there is a season,
a time for every activity under heaven"
You just can't do the same things continually forever. Creation is not designed to do so. I have no reason to believe bulking and cutting seasons are different.
So with that said, you should use "time off" as we call it to prepare for another season of productivity and the secret to this is caloric surplus followed by a caloric deficit. A toggle. Datbtrue tried time and again to teach this secret, and while he found gobs of science to corroborate his theory, nothing confirmed it better than first hand experience. It's not unlike how most of us work 5-6 days in a row and find it necessary to take some "time off" for rest and recreation. We do it with work and our training routines, so why not with the diet and gear? Makes sense to me. And yes, I know this answer is unsatisfactory for those who have to know everything using the latest and greatest biochemistry but I've got news for you: whatever you think is true today will be false tomorrow. The only thing we really have to trust here is our experiences. And it's our experiences that tell us that we better take time off if we expect to 1) stay healthy and 2) continue making progress. Understand that I'm not discounting the effort to accurately and logically understand how things work but I've seen so many instances where real life results frustrate the wise and knowledgeable and this is especially true with two different areas of study - astrophysics and biology. Let's move on...
And finally the practical stuff: I'd use my "time off" doing something like this:
1) Metformin, Berberine, Cinnamon, Chromium, Vanadyl Sulfate - any combination of these will help fix that insulin sensitivity issue
2) Blood Test to verify that my organs and blood is a-ok. This may take some checking and adjusting before you get comfortable with your results
3) Low dose of Test/Mast combo or just Test and mild amounts of Aromasin/Arimidex. Nothing crazy. Just something to keep your serum T around 1000-1200 ng/dl.
4) I'm a big believer in Somatozine now. The stuff does WONDERS for holding onto mass on a low calorie diet. This to me might be a year round staple.
5) insulin as needed to give your beta cells a break
6) something different than your previous diet. I'm assuming it was a high carb, high calorie diet. So I would transition into a lower carb, lower calorie diet and I'd go as low as I could without losing the muscle mass. Probably do it gradually.
I'd do all of these things probably for 6-8 weeks, depending on what the bloods showed. If I was in good health, maybe 6 weeks off before going at it again. If I showed some signs of concern, like really crappy HDL levels or chronically high blood pressure, I might take extra time off and do some cardio in place of weight lifting.
I also realize the chances of you doing exactly what I've spelled out here is slim to none. My general approach always requires a solid dollar and is usually exhaustive in effort to do it right. I'm never going to give a suggestion that is anything less than being exhaustively precautionary. And to be painfully honest again, I'm beginning to teach that broke people should turn away from the idea of bodybuilding and using steroids and gear to cause serious weight gain. It takes a lot of discretionary money and time to reap the benefits of this sport with minimal drawbacks and I almost feel like it is irresponsible of me to drag someone into this hobby/sport/addiction who does not have the discretionary resources to play with. I know that is not what people want to hear because it essentially suggests yet another area that outlines the haves' vs have nots', creating another perception that the wealthier folks are also destined to be the yoked folks but perhaps this can give younger people motivation to go out and make money and live well below their means so as to afford this hobby in proper fashion.