I used to run cross country in primary, middle and high school. I only felt the runners high once, in a competition where I went from middling performance to 9th in the province. Weirdest experience ever. Halfway through the race, I started to feel what could only be described as an orgasm , in my right thumb. I was deeply confused as to what was going on. Then the endorphines spread everywhere and I felt no pain or tiredness. I just kept passing people effortlessly. I had never heard of the runners high and only learned of it later.