Synopsis: Dharkam lays down the gauntlet and says bodybuilding is bad for the testes!
Opinion: I don't agree with many of Dharkam's conclusions in his many articles, but this one piqued my interest.
My belief is that the relationship between bodybuilding and hormone levels isn't influenced only by the training; I think people's testosterone levels decrease at a much lower age nowadays due to many many other factors....diet and the decline in the nutritional profile of our foods and food choices being one.
I do find his postulation that "Statistical studies suggest that muscles can still grow despite a low testosterone output. In fact, muscles growth is more closely related to testosterone receptor density than testosterone level. This indirect finding suggests that testosterone receptors can self activate in the absence of testosterone if muscular contractions are intense enough...." quite interesting also.
The article is pretty lousy imo. His idea of "testicular exhaustion" isn't realistic. How would the testicles become exhausted? The production of a hormone by tissue wont lead to any physical damage/exhaustion, regardless of how much it makes (within reason). It sounds like he has pulled this theory out of his arse. Further, test production fluctuates throughout the day at a far greater amount than the 27% caused by sprinting.
We do know that strength training can increase test receptor density, which apparently means that you get greater response at lower test levels. So your point seems valid there. However with the other crap in the article and the lack of a source (he just says "statistical studies") I would be dubious of anything this guy says. Good post though, it is always interesting to hear new stuff.
I would definitely cite diet as the major contributing factor in testosterone depletion. The lack of essential minerals (zinc,magnesium,chromium,selenium,etc) and vitamin D in the American diet and the high degree of insulin resistance or borderline insulin resistance in the American population have direct effects on hormone production. Vitamin D is the main arbiter of the pituitary's function. The pituitary tells all other hormone producing glands WHEN to produce. At least 40% of U.S. citizens are severely depleted of this vitamin. That likely means a majority are deficient in it. It's the reason supplementing with fish oil has such marvelous effects, since it's high in Vit D as well as the essential lipids needed for proper brain function and inflammation control.
Add in the effect of a superhigh carbohydrate diet, what with processed foods (rich in refined starches) and the additional modified food starch, corn syrup and simple sugars, the pancreas is laboring to catch up, the cells are unable to feed or coordinate (since insulin is a transport agent for energy and hormonal communications in all cells in the body and the cells are no longer responding to insulin) and a general miscommunication amongst all the systems that make up the body occurs. Hormones are produced in the wrong amounts at the wrong times and the creation of testosterone (or lack thereof) is one of the results.
Add in xenoestrogens from unfermented soy sources (endemic in processed foods) and test production can just stop, because you are only nominally male at that point...
I guess that I'm saying I don't agree with the study's findings. Even if it were true, it would be the least cause amongst many others...