One of the most striking discoveries I’ve recently had was the difference between daylight and artificial light. Of course, I could only talk about this from my own experience without having any research to back it up.

So in an incredibly interesting recent study, scientist Mirjam Muench tried to find out about exactly that. They compared two groups of people, one being exposed to daylight, the other to artificial light over the course of several work days. Here is the outcome:

“Compared to the afternoon, people who had DL (Daylight) were significantly more alert at the beginning of the evening, and subjects who were exposed to AL (Artificial light) were significantly sleepier at the end of the evening.”

On top of “sleepiness”, which most of us could probably deal with is the fact that our cortisol levels drop significantly under artificial or poor lighting conditions. That means that we’ll be more stressed, and have less ability to stabilize our energy levels. Here is how a normal cortisol level flow should look like:

So, being exposed to dim light as well as too much artificial light makes both sleepy and also more stressed in the long run. I believe that’s one of the most powerful things to remember. Similar to the science about sleep, paying attention to these rhythms can transform your productivity for the better, not just give you a slight advantage.