Our environment plays a massive role in our hormonal regulation.

As crazy as it seems, something as seemingly innocuous as the lighting around us changes our focus, motivation, performance, and sleep.

Simple changes in our work (or sleep) environment can make a huge difference.

If you feel sleepy during the workday when you should be alert, or alert in the evening when you should feel sleepy, then simple changes to your lighting can reverse this.

First, Understand The Circadian Rhythm

As we’ve written about before, cortisol and melatonin make up what we call the circadian rhythm. Ideally, we want cortisol to be high during the day, and we want melatonin to be high at night. The hormones are inverses. They’re not friends. When one is high, the other is low.

We want to encourage cortisol production in the morning and encourage melatonin production at night.

We can do that in a number of ways, from exercise to sleep routines and plenty of other methods. Today we’re talking about how lighting can do this.

Take An Evolutionary Lens

If you’re not sure whether an intervention will help or hurt your sleep, come back to an evolutionary lens: if cavemen did it in the evening, it’s probably good for sleep. If they didn’t, it’s probably bad.

They did not have blue light in the evening, but they did in the morning. In contrast, they fell asleep close to a fire, which is a red-orange light close to the ground. With this as our frame, the best interventions to maximize your light environment become intuitive.

Blue Light Releases Cortisol, Improves Focus

The first intervention is based on the color of the light.

Because the sky at the peak of the day is blue, our ancestors evolved to be alert and awake in the presence of blue light. In other words, blue light releases cortisol. And it doesn’t just have to be in the presence of our eyes. We have photoreceptors on our skin that also sense the light

That means you can optimize your productivity and alertness with a few simple strategies.

Get Outside Within the First Hour of The Day

This will signal a release of cortisol, and effectively “reset” your circadian rhythm. That’s why this is often recommended to help you sleep at night. In addition to that, it’ll give you a boost of energy during the day.

Take Regular Outdoor Breaks

Taking breaks has plenty of other benefits, such as the primacy and recency effect in learning. For the sake of alertness, though, it will give you little bursts of cortisol, not to mention Vitamin D.

As a simple place to start, try to get outside at least at lunchtime. Eat lunch on a park bench, walk on the block that’s in the sun, go and pick up your lunch, instead of having it delivered.

Work With The Window Open

Even though we see the light through the window, when we’re getting direct sunlight, we absorb exponentially more of the blue light. (Some estimates put it at 50x more.)

If you can open a window, that will automatically give you a boost.

Work With Bright Lighting

Finally, even if you’re in an office environment, you can pick up some bright lights. These don’t have to be fancy or expensive. In fact, a great option I’ve found is to buy a ring light. You know, the ones that influencers use to make the lighting better on their TikToks or Instagram reels.

While we don’t recommend this habitually, if you need to stay up late working and want to stay alert, you can aid that process by keeping bright lights on.

Red Light Releases Melatonin, Improves Sleep

The blue light tip you may have heard before. It’s fairly well-known. What’s less well-known is that red light supports the release of melatonin. In this study, for example, red light in the evening improved sleep quality.

Going back to our evolutionary understanding, this makes perfect sense. Before artificial light, we saw red light at two times: sunsets and in the form of fire. In other words, in the evening.

So red lights evolved as a signal that it was evening, and therefore, that sleep was approaching.

Again, there are a few simple strategies to apply this.

Watch The Sunset

Not only will watching the sunset flood cause a flood of sleep-promoting sympathetic hormones, but watching sunsets is one of life’s great joys.

The sheer beauty of it alone, makes it worth going out of your way for. The fact that it’s also good for your sleep and productivity is a bonus.

Get Red-Light Spectrum Lamps

After sunset, try to switch the lighting in your house from the normal overhead lights to lamps with warmer, red and orange lights. These mimic the presence of fire, and support our natural circadian rhythm.

There are tons of companies with fancy red light products and all of that stuff. But, simple $20-$30 lamps you can get on Amazon or any other big store will for sure get the job done. Put them in your bedroom, in your living room, and anywhere else where you hang out at night.

Light a Few Candles (with caution)

If you just need a little bit of light, you can go with a few candles. Just be careful. Don’t get mad at us if you light your house on fire.

Overhead Lights Increases Productivity

One study of office workers found that people were more productive when the lights were overhead.

This sounds kind of nuts, but again, going back to our ancestors, it makes sense. It’s not only that the light in the sky is blue, but also that the light in the morning and afternoon is above us.

That means if you want to be more productive, the next best option besides working outside is to turn on lights above you. In your office environment, it might be worth it to install blue lights on the ceiling to give an effect of a blue sky.

Bottom Lights Mimic Fire, Sunset

On a similar token, in the evening, try NOT to take in overhead light, even if its red. We don’t need to change the prescription, because we already suggested that you get red-light lamps and place them around the house.

If you have the choice between lower on the ground and higher, place them lower.

Evolution is the Background For These Discoveries

These are all simple, inexpensive strategies you can apply with pretty much zero downsides or risk.

One common theme among these interventions is the research consistently affirms what evolutionarily makes sense. When we think about things like sleep, performance, and productivity, one of our first principles should be to think about how we evolved.

In these cases, the impacts of different kinds of light make complete sense when we think about pre-modern humans and pre-artificial light societies. And while our society has changed a lot, our biology hasn’t.