I used to regularly push over into a sort of manic trance when I did long runs in high school and college. I certainly never got as far as Robic (maybe the clos

I used to regularly push over into a sort of manic trance when I did long runs in high school and college. I certainly never got as far as Robic (maybe the closest was when I did the New York marathon in 2005). I could obsessively focus for long periods of time on the smallest thing (like watching my hand jump in front of my eye) or a word or phrase. But I don't think I ever hallucinated anything or even got to the point where that could happen. I'm kind of inspired to try. Word of caution: I think if you'd like to try, you should make sure your body can support the level of activity needed to get to that barrier. That means you shouldn't just try to run 40 miles right away. You're more likely to injure yourself. You need to build a high quality base of fitness before you attempt something drastic otherwise you might be out of the game for weeks or months.