Runner's High

Everyone has heard of concept of runner's high. Webmd.com describes runner's high as the "experience [of] euphoria, a feeling of being invincible, a reduced state of discomfort or pain, and even a loss in sense of time while running." Sounds like a pretty great thing, and possibly the only way for me to get through my big half marathon. There are questions about what exactly causes it: endorphins, neurotransmitters or body temperature, but there is no debate that it does happen. And it makes sense to me that it happens most often to marathoners. Humans aren't supposed to be able to run 26.2 miles. The human body can only store enough energy for about 18-20 miles and this when people "hit a wall" while running. While people do try to train to prevent this from happening; I think the body responds by giving you this feeling of euphoria or the runner's high. I haven't experienced it yet, but I hope one day running will stop being a low and move on to that high. And the picture is what I think of when I think of the runner's high.