its extremely dangerous....i would advise you to not use a ring while doing it. Until really advanced in pe or rolling pin excercise
++++ ^
Most people will not be up to adding pressure while using constriction. You can pop a vein (or worse) reallllly easily like that.
With exercises like that (which, I did them all .. so this isn't a 'general' warning) you Must go slowly and build up to it.
And then ..
Stop going further.
Beyond a certain amount of doing extreme exercises, More is no longer 'better' .. beyond a point More is just More Dangerous.
If you Must add something ... add Time , or Sets , instead of adding more and more pressure.
There are (as always) multiple ways to do the rolling pin (etc) type of exercises. Another way is to use a ceramic tile (or a hardwood flooring sample, etc) to add the pressure against a desk or table, .. like a 'smashdick sandwich'..
Doing exercises in only that direction, down,
Will eventually effect your shaft shape and make it
flatter instead of round.
A bit of that can be aesthetically pleasing, and might even add more stimulation to a chick's clitoris in certain positions (and based upon the spacing of her particular gear), but it will also make your dick more likely to encounter potentially really dangerous Bending accidents during misalignment mistakes or energetic sex generally. Look up the injury rate for Reverse Cowgirl (it being both energetic and potentially misaligned). A flattened shaft shape increases the chances of injury of that type (
bend/snap), so don't go nuts with shape changing.
Another way to add similar (if not superior) girthing pressure is to squeeze your shaft between the palms of your hands with fingers interlaced (to function as a hinge) and pressing the palms/thumbs towards each other to add the pressure. It's a bit like your entire hands are forming a giant cableclamp. This can be a LOT of pressure so don't fvckup, go slowly and build up to any extreme exercise.
The palm-clamp ^ (or whatever name it might have) can also be increased even further in pressure, and Danger, by performing the exercise between your legs and closing your legs to add even more pressure than you can manage with hand force alone. I got my
Only real injury in my ~fifteen (?) year PE history doing this exactly (while constricted), so watch the eff out with it and don't go too gung-ho (!) , but to finish the thought .. these build girth in an -even- manner, rather than thinning your shaft-shape like rolling or tiling can.
You can also (instead of parallel at the same time) apply the palm clamping pressure from the bottom to the top to simulate a jelquing or Uli motion in repetitions, ..as well as move the opposing palms up the shaft when closed to further simulate jelqs/Uil's .. for stimulating additional simultaneous formats of shaft and glans stressors that wouldn't be available with rolling and tiling.
IIRC I would do these for time-reps of 20 to 30 seconds each, for 3 or 4 reps, maybe 10 seconds between reps, and then massage out for a bit, (obviously release the cableclamp if I was doing them clamped), and then repeat until it seemed like 'enough', probably never more than 20 total reps and usually at the end of a session because it's intense and afterwards you're kinda done.
I do want to sound like I'm admonishing, more than romanticizing, ... it can't be overstated to Be The Fvck Careful. Doing these was during the period that I was going the hardest that I ever went. None of it was like 'going through the motions'. Afterwards it was much more likely to feel like "OMG, i hope I'm Okay..". and that's going too hard. BTFC ^
