Runners High is this thing that runners talk about all the time. This perfect moment where running feels as natural as breathing.

You never hear about cyclists high. In fact if you do a Google search the number one hit for “cycling high” is an article about a different kind of high while cycling…

Cycling is this brutal, painful and annoying activity. Unlike running, cycling makes this promise that you’ll never injure yourself unless, you know, you hit a car or fall off.

After a week in Hawaii where I ran and swam, cycling was a pain in the ass. Literally. And my muscles felt horrible while cycling. And yet I was able to move faster and stronger than I had in a while. Which was confusing. Here I am making real progress in my ability and performance and simultaneously it feels worse.

What is going on?

Well the Scientific American has an awesome blog post on the topic. And if you read through the comments, you’ll find this theory:

Dulling the pain is only part of the evolutionary rationale, Scicurious. The main reason for runners’ high was to amply reward ancient long distance running hunters for engaging in this vital yet highly taxing pursuit. (Sex is so gratifying for precisely the same reason.) Many athletes who are both runners and cyclers/ swimmers (like myself) insist that while all sports can provide equally strenuous workout, nothing compares with the euphoria induced by running. If cycling and swimming had played similar role in our evolutionary history, they’d also produce comparable highs…

I like that. The reason is there is no such thing as cyclist’s high is that our ancestors believed in running not cycling.

So there you have it, runner’s high is an evolutionary response. Which means the reason Pheidippides ran the Marathon was because he was in a drug induced haze. And explains why the Ironman finishes with a run… we need that drug induced high to make it through the pain…