OK so here's the deal, I have been running relatively high mileage (80-100) for the last few months. In that time period, I have noticed that my sex drive has effectively become non-existent. Additionally, I don't seem to get as nervous/excited for races as I used to; the competitive drive/"killer spirit" seems to have died down as well. (I am a 20 yr. old male for reference.) Has anyone else dealt with this kind of problem? Does anyone have any tips/solutions? Could it be due to a lack of some vitamin in my diet or something?