I've never run a marathon, but I'd imagine it's trying enough without thousands of volts of electricity coursing through your convulsing, naked frame. Yes, naked - as was the case for Ohioan Brett Henderson. He didn't win the marathon.
Henderson (seen above, clothed) was tased into a heap and charged with public indecency and obstructing official business after refusing to stop running naked in the Cincinnati "Flying Pig Marathon" - I'd insert some sort of lazy bacon joke here, but really, the image of a naked running man struck with a taser should be enough for us all. [Cincinnati.com]