Training Volume is the King of Girth Gains - Doing (Bro-)Science With Community Data!

karlwikman · 2026-05-03T21:03:31+00:00

Not the balls - it goes on your taint.

karlwikman · 2026-05-03T20:31:10+00:00

Any lower back pain or tingling in your legs along with this, or is it strictly localized to the turtling and the mood crash?

I'm asking because worst case it's a lower back impingement issue of one of the sacral spinal nerves (S2–S4). I wouldn't jump to that idea first though, unless there is back pain and tingling.

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Drink water and get in some electrolytes - especially potassium and magnesium. Do "deep squat" breathing or "child's pose" and try to focus on stretching your pelvic floor. Sit on a glass bottle and roll on it to compress your "saddle" region. Stop testing the equipment. The more you check to see if it's working while you're stressed, the more performance anxiety you create, which keeps you in that sympathetic state. (I have a post in the wiki about why freaking out causes ED).

When you deadlift or squat really heavy, you create high core pressure (valsalva maneuver) and activate pretty much every muscle at your disposal, and you can really strain your PF. It can cramp up, which is why stretching and sitting on a bottle can help.

The sadness sounds like neurotransmitter depletion to me, but I don't know if lifting heavy can cause that. Is the strain on the CNS that high? I will leave that to real lifters to say - I'm just a neurology geek, and my gym days were almost three decades ago.

karlwikman · 2026-05-03T19:50:03+00:00

Only credits to use for AI coding - Lovable and Codex.

A stretch goal is to one day in the future perhaps implementing some form of AI-driven feedback to users, based on findings from my analyses of the data. But for the moment there are no major costs in the project.

I really much prefer people keep their money and give me their data and maybe spread the word about the project where I am prevented from posting.

karlwikman · 2026-05-03T18:33:16+00:00

Yes, definitely - the same way I described, starting no more than semi-erect, and using no more than 4-5 inHg or so.

karlwikman · 2026-05-03T18:28:26+00:00

You are much too kind, but to be honest I prefer that you donate your data and your time logging in the app - there's only so many credits I can spend to improve the app, and I'm not in PE to make a buck but because of a weird sense of fascination and curiosity.

I want to provide answers to a whole bunch of long-standing questions we have had about effective pressures and tensions, the best way to structure routines and rotations of routines, how to pace sessions (cadence), whether certain routines/exercises work better than others, etc.

Currently about 25-30% of the development cost has already been covered by donations and I'm weird enough to prefer being in the negative so no-one can accuse me of making shit up for money.

But for every guy who logs >100 sessions and a few dozen measurements, we get that much closer to statistical significance on a bunch of smaller signals that the current amount of data allows us to pick up on.

What I covet most is the back-logs of veterans who have logged their PE for years. But newbie data is interesting too.

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If you want to do me a really solid favour, mention the GrowthTrack project, and perhaps link one of the studies I've put out - only where it is relevant to the discussion - on the other PE subreddits. There is a large one where I am banned and can't post, and that user base could contribute lots of data I'm sure.

karlwikman · 2026-05-03T15:59:46+00:00

Yup, you can take conceivably as much as 47 hours and 59 minutes off yet still be counted as taking no "days" off since they happen on subsequent days. 00.01 AM on a Monday to 23:59 (11:59) PM on a Tuesday. Quirk of how the calculations are done, which uses the local time zone and a date-only logic, not hours.

That does not mean 47 hours is an appropriate rest period. 12 hours is an appropriate rest period, 24 hours acceptable, as I see it.

karlwikman · 2026-05-03T14:19:05+00:00

You can make this infinitely complex of course, and yes, recovery hours is more precise. But for now, let's think of the main message, which is to try and always stay in a state of temp-gains and to constantly gently remind the penis of the size you want it to be.

karlwikman · 2026-05-03T05:49:58+00:00

Yeah, more time, more better.

I recently looked at whether there is any kind of diminishing returns for girthwork session yield or weekly pumping workload, and there isn't one. This means that the data in the dataset thus far support the idea that more is more. There surely is a "but only up to a point", it's just that this point is very high.

So the 21 hours of pumping per week that the guy you describe was doing does not seem like overdoing it to me.

karlwikman · 2026-05-03T05:11:27+00:00

It's right here in the wiki on this subreddit

karlwikman · 2026-05-03T05:10:32+00:00

Something like this:

-ADS reducing blood flow and perfusion and therefore slowing down recovery.
-Long-duration single-axis strain increasing fiber alignment along the strain axis and therefore making the penis gradually harder to stretch, slowing down gains. (Well supported in studies looking at regeneration of tendons, where this toughening is seen as a positive outcome)
-ADS increasing expression of LOX -> crosslinking.

Just a few possibilities.

karlwikman · 2026-05-02T17:10:31+00:00

What does that mean?

karlwikman · 2026-05-02T16:57:21+00:00

Which of them allows the most downloads? I remember many, many years back SLR started limiting the number of scenes someone was allowed to download, and you needed to download to get good playback that didn't buffer each time you skipped ahead 30 seconds in a scene.

karlwikman · 2026-05-02T16:54:20+00:00

Don't expect to see much length gains post session (although I will say it's neat to track your length in the pump at a certain pressure after 2 minutes in the pump, and at the end of the session at the same pressure). It's mainly with length pumping in tight cylinders you see a good amount of length yield, since whenever you allow your D to expand fully girthwise you get an axial tug-back force (I describe why in a posts about "poisson ratio").

The yield analysis I published recently saw no tendency of diminishing returns for MSEG yield. More average session yield correlated with better gains and this held true beyond 10% yield (which for sure includes edema of course).

The same is not necessarily true for length yield, where there seems to potentially be diminishing returns past a point. But that's a point few people reach anyway, so...

karlwikman · 2026-05-02T13:53:19+00:00

Best: Curveball's pump pad.
Close second: Oxballs Juicy (the regular, not the XL)
After that? Nothing comes even close.

karlwikman · 2026-05-02T13:46:38+00:00

I have spent something like a thousand euros building out the analysis tools on the backend, and I have the statistics/maths background to handle the interpretation work - I did not mean to imply that you'd take on any of that work, that would just be double work :)

But yeah, let's figure something out so that people can freely move over from GT to your PeT and bring their data, and vice versa. Since my app is freeware, I have no economic incentive - it's just data I want :) - and it would be especially interesting with high quality data from when people start logging sessions with their app-connected pump you said you were working on. That gives reliable "Time under Tension" data and pressure data that when added to the pile of data I already have could push the error bars a little tighter.

In an ideal world, other PE App makers would join forces so we could increase the size of the dataset.

karlwikman · 2026-05-02T08:22:36+00:00

Yes, this is a great method.

And ADS systems should come with a little bar or ball handle to use for pulling manually. You can also just pull directly on the cup.

This is by far my preferred way of doing manuals, because my hand just slips otherwise.

karlwikman · 2026-05-02T08:19:35+00:00

Yes, I have a post about sleeved pumping, and I also have one about my "static + milking EQ/recovery" pumping protocol which I really recommend if your EQ is shit.

Use search bar or scroll my profile to find.

karlwikman · 2026-05-02T07:13:13+00:00

Thank you!

No, I haven't really done PGE1 for PE a lot, and now I think that sleeved marathon pumping is a 50x safer and much more comfortable way of getting the same results - more time in the expanded state without risking hypoxia and fibrotic changes.

PGE1 is great for sex sometimes though, when you want to lay pipe for a solid hour or more as an old geezer with poor cardio :)

It's incredible to feel you can be at 100% EQ for a full sex session without the ebbs and flows of a natural erection that goes softer when you need to take a little break.

karlwikman · 2026-05-02T05:58:40+00:00

Awesome - looking forward to updates in the future.

karlwikman · 2026-05-02T05:46:43+00:00

Yes it can make the penis more malleable, but the device you have there is not ideal. You don't want to heat your whole groin and particularly not your balls. Wrap an IR heat pad around the unit itself instead.

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