No offense dude, but you need to study a little anatomy. The kidneys have notheing to do with semen - they are separate systems. Nor do sexual activity, mental activity, sleep, etc. alter kidney function. The kidneys are the primary regulators of acid/base balance in your body - if their function fluctuated so whimsically, we'd all die much younger deaths, and definitely wouldn't be able to withstand the abuses we put our bodies through when we're young.