I think the reason that you can’t find anything specific is there’s no established criteria for increasing time or intensity other than tracking your results and reacting to how your body responds.
You can track training results each session (elongation rates for length training or girth expansion rates) or track your results over longer durations, like weekly, monthly or quarterly.
With per session measurements, if you’re hitting your session targets consistently using a stable approach with few variables (like you use the same weights and durations, heat or no heat, or the same vacuum and durations for pumping) then over time you should be increasing in baseline size even if permanent results come in unevenly. If you have a consistent period (say a week or so of training sessions) where your training results in significantly undershooting your targets and previous results, then it is time to increase intensity, duration, both, or take a deconditioning break.
Pumping is a little tricky since expansion includes some degree of edema which is pretty highly variable from session to session. But if you are paying close attention and using similar intensities and time it should be relatively consistent, especially if you know how to keep superficial edema to a minimum.
If you use longer time frames to track, the same approach applies, just less frequently. Say you measure every month. If you are consistently growing then don’t change anything up. If you stop growing then same approach to the next period, either more intensity, time or a break to let the tissues soften up a bit.
Keep in mind that as you get larger at some point the returns come in slower and slower. So the sometimes rapid gains you make early in your path will slow down and this isn’t necessarily an indicator that you need more training. It’s just a fact that each mm becomes harder to earn.
So there is an art component to the ‘science’ of PE, and that is learning your response to stimulus over time and changing conditions. The best tool in the toolkit is finding a consistent and reproducible way to measure and a spreadsheet to keep track of response over time.
Check out DickPushup’s progress log thread. He is masterful at tracking training response. You might get some ideas on how to track your own training from him.
Hope this helps.
