We all know the first mile is a lie, but this last weekend I was able to conceptualize and validate another of trail running’s natural laws, the Law of the Conservation of Misery. It is awfully tempting as one of the sport’s foremost scientists, to name this law after myself, but I don’t want to be associated with misery any more than I already am.

Here is the thesis: The amount you suffer in any run or block of runs remains constant. If the first mile somehow feels fast and flowy and easy, the hard part will come later, inevitably. If, instead, the first mile is very hard, things will get better. The amount you can hurt ebbs and flows, but over time it is fixed.

Just to pay homage to the inspiration for this ground-breaking bit of running science, let’s summarize Einstein’s Law of the Conservation of Matter, which holds that matter can neither be created nor destroyed. It can only change form.

In running, this is how suffering operates also.

There is a remaining question about the underlying causes for this perfect system. Does the runner, having enjoyed a relatively painless jaunt, subconsciously turn up the effort to achieve some level of cathartic pain? Or does the pain itself hover over all of us, randomly alighting on our unsuspecting shoulders, just to remind us we are not in charge?

Further research is clearly necessary.