Why Running In The Dark Feels Faster

Why does running in the dark feel faster? EndurElite Chief Endurance Officer Matt Mosman discusses optic flow and how it can change your perception of how fast and how hard it feels like you are running

Full Video Transcription:

Good morning, Family of FAST. Matt Mosman, the chief endurance officer over at EndurElite. Have you ever wondered when you run or cycle in the dark that it feels like you're moving a lot faster, that you may be working a little bit harder but when you get back and you check your GPS that that's just not the case? Well, there's a perfectly good explanation for this and it has to do with something called optic flow.

What Is Optic Flow And What Does It Have To Do With Running In The Dark?

Now, in the simplest sense, optic flow is how you're are gauging your movements or speeds based on your surroundings or the objects in your surroundings. So, as an example, if you're running during the day and you see a really tall building off in the distance, it just feels like it's really moving slowly towards you. And then on the other hand, if you're running in the dark you can't see a lot around you and then an object pops out of nowhere, it feels like you're just moving fast and blowing right past it, hauling balls.

The Research On Optic Flow In Cyclists

So, in both those scenarios that is optic flow and there is actually been some research done on optic flow that was conducted at the University of Essex and then published in the "Journal of Sport and Exercise Psychology." And they wanted to examine how optic flow affected rating of perceived exhaustion or again how hard you're working. Now, usually these scales or these RPE scales will be anywhere from 0 to 20,with 0 being the easiest and 20 being like I'm gonna vomit and my legs are gonna fall off.

So for this research study, the scientist took 15 elite level cyclists and had them perform 4 different 20 kilometers time trials on a bike. Now, for the first time trial it was just served as a reference point, they did this 20 kilometer time trial as fast as they could. Now, here is where it gets interesting. For the next 3 20 kilometers time trials they put the cyclists in front of projection screen with like a cycling course. On one occasion they projected on the screen how fast the cyclists were actually moving. On another occasion they slowed it down by 15% and then on another occasion they sped it up by 15%.

Now, during this whole time for each of these time trials the researchers were looking at the cyclist power output and rating of perceived exhaustion every four kilometers. So after they crunch all the data here is what they found and I'm gonna read this verbatim from the study. Even though they was no difference in heart rate or cadence between each of the time trials, the cyclists underestimated their exhaustion when the scenery was going by 15% slower than when the scenery was going by more quickly or in proportion to their speeds. So, in other words the cyclists didn't really feel like they were working as hard when the scenery was going by slowly.

So, does this mean for you? Well, at nighttime when you're running and again an object pops out of nowhere, it all again has to do with optic flow. That's why it feels like you're running faster because you don't have the whole visual of all your surrounding and objects off in the distance compared to when you are running during the day times. So, it's going to feel like you're working harder and running faster even if you are not. So, what's really the take-home? Well, the dark is really messing with your ability to properly gauge your speed and intensity, is what it comes down too. Even if it feels like you're moving fast, you probably really aren't, all based on this thing called optic flow.

So, that is all I have for today my endurance friends. If you have a buddy that runs or cycles during the dark, he's like, "Man I was hauling," please share this video with them and say, "Sorry to be a party popper but that's not the case." If you want other videos like this on endurance training, nutrition, supplementation, other random musings, busting the BS, subscribe to the EndurElite YouTube channel or head on over to the EndurElite blog at www.endurelite.com. Get social with us on Instagram and the Family of FAST Facebook page. And until next time my endurance friends, stay fueled, stay focused, stay fast, and stay informed.