I don't see how it could make you sterile...?? What did the article say, exactly? Or was it just hearsay from another forum or something? To get a "hang" going, start out with DLDs "Testicle Health" routine, then work up to getting some leather ball stretchers. Then of course there's tons of info here on more hardcore ball hanging (from Supra and some other guys) using different kinds of weights/devices. I've been doing it for a little while and have seen pretty quick results from the test. health routine and leather ball stretchers (get the more expensive ones with the metal snaps; the cheaper ones with velcro usually arent' rigid enough leather to get a "real" stretch , tho some guys might report otherwise). Start with a small stretcher and work your way up. It's an altogether NEW sensation, I might add...not always comfortable, hehe! (esp. not at the beginning).
Ball hanging , with heavy weights and stuff I could see that have the ability to make you sterile. The whole ball area is extremely touchy/sensitive. Much less tolerant than the penis itself.
Also with the stretchers/hangers I thought it was because the balls naturally descend and recede to keep a stable temperature. Since sperm is generated at a lower temperature than the body it has to go lower to cool down to stay at that optimum temperature. If you trap it, with a device like a leather ball hanger or weights, it cannot ascend to re-heat itself if it gets too cool. Which over time I could see leading to some fertility problems.
Best bet would be to read through the threads that have occured here. I believe that issue has come up. As well as finding everything you can from credible (emphasis on credible) sources before you go ahead with ball exercises. And if you do, be uber careful!! Good luck!
Well I for one have been using weights for over two years now and have always had a nice hang but the "cold curl up" pissed me off. So I use weights at night and weekends when clothing permits. During the week I use leather. I havent had any sterility problems. But thats just my case. I cant speak for all guys. I for one LOVE to hang some split collars on my balls its great!!!