We turned up the hill by the steep route. We normally take the switchbacks, the longer, easier way, but today I had a wild hair betwixt my cheeks, so I went for the hard way.

This used to be the only trail to the top, and I got to know it well on my mountain bike. It goes steep, flat, steep, but in that second hard section there are some logs across the path that challenge you to generate enough speed to clear them even though you’re already in the red. This isn’t such a big deal when running, but your heart will jump out of your chest if you try to attack, as I sometimes do on a shorter climb. This one is just about 50 meters too long for that approach.

The word symbiosis, which describes two organisms who combine their efforts to get things they both need, is much abused. We use it all the time when we describe things that cooperate well, or that appear to be in sync with each other. I’m going to abuse it in exactly that way now.

M and I, as I said, turned up the hill, and I immediately went to dial back my speed and try to get my heart rate into a manageable rhythm. We were both huffing audibly at this point, and I was struggling to isolate my own breath in the noise. My brain kept forcing me into the pattern of her inhalations, and I almost started hyperventilating before finally our two breaths synced up, and I settled in.

It sorta freaked me out, because for a solid five or ten strides I really couldn’t separate our two breathings. It was as if I’d been overridden at brain stem level.

By the top, we were striding in time, the short, choppy steps of steep ascent, and I felt myself rising easily to the place where the trail empties out at the water tower.

I am, by nature, an introvert, but I run and ride so much better when I have a partner, and it might be this sort of vampiric attachment I make that lets me moderate my effort better. Even when I’m running with someone of a different height and stride length, I find my footfalls line up with theirs eventually, like I need to offload pace to the other person.

This is less true on the bike, for obvious reasons, but when I’m behind another rider on the trail, I will use their line as a guide (I think we all do this), so that I seem to be pedaling down a track they’ve laid, only darting off occasionally to grab some other obstacle by whim. Their line is the reference point, and it frees me from the harder job of choosing in advance.

By the book, there are three basic types of symbiosis. One is mutualistic, where both organisms benefit from their association. Pollination of plants by birds is an example. Another type is commensalistic, where one organism benefits more, but the other isn’t harmed, like hermit crabs using the shells of other animals for protection. The last is parasitic, where one benefits at the other’s cost, like a tapeworm.

As I said, we headed up the hill together.

Image: By Brocken Inaglory – Own work, CC BY-SA 3.0