First of all, this is a clinical discussion about biology not morality. If you feel guilty about masturbation or are wondering about the morality then stop reading now and talk to your parents or someone at your church. If you might be offended, please read no further.
“Masturbation reduces your testosterone levels so you cant build muscle” / “Masturbation depletes you protein reserves so you cant build muscle” / “Masturbation will cause one arm to disproportionately large and muscular”
Surprisingly I have gotten many questions about this subject otherwise it would have never occurred to me to include this but apparently there are many myths about bodybuilding and masturbation. Lets take the first one, “Masturbation reduces your testosterone levels so you cant build muscle”. Sex drive is a result of testosterone, not the other way around. There has never been a study which even hinted that masturbation might reduce testosterone levels. Lets take the second one “Masturbation depletes you protein reserves so you cant build muscle”. OK, this is just ridiculous. Think about the amount of protein that leaves the body during masturbation, maybe 5cc’s that might contain 1 gram protein, and compare that to the daily protein intake of a bodybuilder which is approx 200g.
Another way to think about this, if this were true it would mean that no elite athletes would ever be allowed to have sex. With all the money in pro sports, you can be sure that if there were any truth at all to this that coaches across the country would demand total abstinence from all their team members. The grain of truth that probably got these myths started comes from the fact that typically after release, the person is very relaxed/tired. I have also heard people say that various other trace elements, like zinc for example, are expelled from the body during release which just does not make sense. Why would evolution favor a someone who routinely got rid of essential trace elements and make himself weak doing it? High testosterone levels correspond with high fertility and increased sexual activity, it makes no evolutionary sense whatsoever that this sexual activity would weaken the body because the evolutionary goal is to produce as many strong offspring as possible.
Now what about this myth, “Masturbation will cause one arm to disproportionately large and muscular”. We all know how difficult it is to build muscle. If it were that easy to build arm muscles then everybody who wanted big Popeye-like arms would have them. If your arms are different sizes, masturbation is not the reason. Very few people are symmetrical and it natural for their dominant arm to be larger, nothing you do for a few minutes a day will have any affect on the size of your arms.