Another killer of testosterone is stress. an attorney may go home at night worrying that his client is innocent and may go to jail for life, while an md may worry his patient will die on the operating table if he fails to do his job right. generally speaking though, a plumber may exercise more during his work and burn off potential excess cortisol levels, whether he worries or not about your pipes breaking in the night, or worries that your toilet will overflow so high that you'll drown. people under high stress tend to drink more and smoke too and both cause t levels to plummet! there are many reasons t-levels may decline. and, even the speed of the genetically-coded aging process may be more modulated by testosterone levels, than many had previously considered.