The Human Evolution Blog

It used to happen to me all the time at work. Running late for a meeting and it’s only one flight up, so I dash up the stairs. I then arrive at the meeting huffing and puffing like I’d just run a mile. It was ONE LITTLE FLIGHT OF STAIRS!

In my late 20s, I was not in particularly good shape. I was fairly thin, but no regular exercise routine, so I blamed it on that. In fact, “winded by one flight of stairs” is an oft-used expression for indicating someone is out of shape.

But then I became a runner. At first, I could barely manage a quarter mile without stopping, but I worked hard at getting in shape. I worked up to several miles within a few months. A couple years later, I managed a half-marathon in 1h 55m. I’ve been a runner for almost ten years now and my typical run is 7-10 miles.

And I still get winded by one flight of stairs. What is going on???

It took a bit of research to figure this out. While it’s true that this wouldn’t happen if I were warmed up and exercising, there’s something else at play here as well.

The reason we all get winded by running up one flight of stairs is because we stop breathing when we do it. Humans and many of our close relative species have a tendency to stop or slow our breathing when we concentrate on a specific task for a short period of time. When you are dashing off to that meeting at work, you approach the stairs and aim to dart up them quickly. This boots up the “concentration on small task” program and your brain actually slows down your breathing. You may even hold your breath up the whole flight.

The result of this, of course, is that we combine a small burst of oxygen consumption by our muscles with a small burst of oxygen deprivation by our reduced respiration at the very same time. Together, these two forces make our blood oxygen level plummet suddenly and our brain takes notice, signaling rapid breaths to compensate. (It’s actually a spike in carbon dioxide in our blood that is the actual trigger, but oxygen and carbon dioxide concentrations in our blood are inversely related in all normal circumstances.) We stop breathing exactly when we need to be breathing more. This catches up with us after we scale the flight of stairs and we’re left winded.

But why do we stop breathing right when we should be breathing more? It seems that this reflex evolved to help keep our bodies still when we are focused on a physical task that requires concentration and precision. Imagine threading a needle, making a surgical incision, aiming a rifle, or throwing a dart. The key to being precise with these coordinated physical tasks is quiet concentration. By slowing or stopping our breathing, we reduce the background movements of our bodies and, hopefully, achieve better accuracy in the execution of our carefully planned actions. That’s the idea anyway.

Some people even report apnea (temporary suspension of breathing) when they are typing, chopping vegetables, looking for something in a drawer or refrigerator, drawing or painting, or any other task that requires momentary concentration.

One can imagine how useful this feature is in our animal cousins, who must make their living in the wild, as well as our ancestors in the African Savannah. From time to time, this trick likely made the difference between eating and not, and that’s a clear evolutionary value and a clear selective pressure.

Try this. Next time you are dashing to a meeting at work, concentrate on your breathing and deliberately take some deep breaths as you approach the stairs, and continue to breath as you scale them.

I suspect you’ll notice a big difference. I did. If you do this every time, it will become a habit and, problem solved – you’ll never arrive at a meeting huffing and puffing again!

-NHL