Habits Productivity

Circadian Rhythm: the Ideal Time Schedule for Optimal Productivity

By Jon Rumens on 21 August 2019

Sleep is really important. We all know that.

A common thing people hear when they want to know how to be more awake and focused during the day is that they should sleep enough, and be sure to get their eight hours of snooze every night.

Of course, there is a lot of truth to that. But it’s not the entire story.

You see, the amount of hours that you spend asleep is not the ultimate, decisive factor in how rested you’ll feel the next day (but an important one nevertheless).

For example, it’s very possible to get ‘enough’ sleep every night and still feel like a zombie when you get up in the morning. Most likely, this is due to the fact that you’re neglecting your circadian rhythm.

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Circadian rhythm 101

If you’ve ever heard of the ‘circadian rhythm’, this was most likely in the context of sleep, in which it plays a very important part.

For those of you who aren’t familiar with it, I’ll give a quick explanation: basically, our bodies have evolved to be adapted to the light/darkness cycle, a cycle that is about 24 hours long.

Because of this, it’s called the circadian rhythm (circa dia=about a day). This adaptation causes our bodies to be active during the day, and rest during the night.

Now, the circadian rhythm isn’t just for sleep, it does a ton of other things as well. It tells your body when to make certain hormones, neurotransmitters and other substances at any time of day, because it can’t do all these things at the same time.

Basically, it’s your body’s daily to-do list.

You can use this clock to plan out your daily activities (be sure to be near a bathroom at 08:30)

Some examples of what circadian rhythm influences:

  • General health and risk of disease
  • Energy regulating hormones
  • Stress and youth hormones
  • Metabolism and appetite regulating hormones
  • Sleep/wake cycles
  • Arousal and alertness

To know what your body is supposed to do at a certain point during the day, it needs to know what time it is. For this purpose, we have an internal, biological clock.

But this clock gets out of sync really easy. It constantly adapts to the environment and needs the right signals to be able to tell the time. These signals are also called ‘zeitgebers’ (which is German for ‘time givers’).

There are many zeitgebers, like movement, temperature and food intake, but the most important one, above all others, is light exposure. When light enters our eyes, it activates a part of our brain called the ‘suprachiasmatic nucleus’ (SCN), which is more or less our central clock.

Brain, meet light

Light is basically the signal that tells your brain: ‘Hey, it’s daytime, it’s time to be active and get going and start hunting and gathering and do other stuff to survive.’

Now, what’s the big problem?

One issue we have in the modern world is that we sit inside all day, we hardly move anymore, we eat and snack from the break of dawn until late at night, and we have access to heating, so we’re always exposed to room temperature.

Because of this, it’s very hard for our bodies to figure out what time it is, and what it’s supposed to be doing at any given time of the day. The most noticeable effect is on sleep, which definitely suffers a lot if your circadian clock is out of sync.

And one night we go to sleep at 10 PM, the other night it’s 1 AM, and so on.

All of this is very confusing for our body and continually disrupts our internal clocks.

Not only will you sleep less and find it harder to doze off, the quality of your sleep will be diminished greatly too.

This by itself is more than enough to lose focus and concentration and productivity, but there are secondary effects as well.

For example, our bodies are primed to be much more wakeful and focused in the morning, before noon. When we wake up, we get a shot of cortisol which wakes us up and makes us alert and vigilant. In short, we get a huge mental boost.

But as the day progresses, the hormones that are present in our brain and bloodstream change again, and we become calmer and less wakeful and less mentally focused.

By the time it’s evening, you should be mellow and relaxed, in other words, completely prepared for a good night’s sleep.

Unfortunately, because our circadian rhythms are out of sync, we don’t really experience this mental boost and clarity in the morning anymore. We have a hard time getting out of bed. A lot of people need caffeine just to be able to get going and start working.

We stop noticing any big difference between morning and evening, between night and day. It all feels the same to us.

Many people accept this as a normal way of life, while in reality, this is completely out of touch with how we should feel and live.

So, even if you do get your eight hours of sleep every night, that doesn’t automatically mean everything is peachy. If your circadian rhythm is weak and your clocks aren’t working properly, your health, focus and productivity are going to suffer noticeably.

Obviously, if we want to improve our focus and productivity, we have to make sure to get our circadian rhythm in working order.

Okay, cool, so how do I do that?

Well, the solution isn’t that hard. You just have to think like this: what would be the natural way of life, and then figure out ways to mimic that as well as you can.

Imagine not living in a house or spending your day inside an office building, between four brick or concrete walls, with hardly any light exposure. Instead, imagine spending your day outside, exposed to massive amounts of sunlight.

Even when it’s cloudy outside, the amount of light that our eyes are exposed to are vastly higher than the amount of light you’d get from a light bulb.

Whereas inside you might get something of a 100 lux of light exposure (that’s the measurement unit of light), when outside, you can be exposed more than 100,000 lux.

The differences are vast, and your brain will notice this too.

The best way to improve your circadian rhythm: lots and lots (and lots) of sunlight in daytime

So the most important thing you can do is to expose yourself to sunlight as soon as you wake up. Open up your window blinds, drive your bike to work instead of driving your car.

If that’s too inconvenient, you can also buy a special light box that gives off high amounts of blue light (which is the kind of light that wakes you up) and make sure your eyes are exposed to that in the morning. At noon, you should try to go outside for another short walk so you can get some more light.

The opposite goes for the evening. In the evening we’re not supposed to get any blue light exposure, which means it’s important to dim the lights and not spend the entire evening in front of the TV or your computer playing video games.

Gaming at night: not the best thing to do if you want to feel wakeful and focused the next day

One other thing you should do is make sure your bedroom is completely dark at night. Science has shown that even a tiny bit of light can throw off your circadian rhythm and impact the quality of your sleep.

It’s also important to get more movement and don’t try to sit on your behind all day. Lots of activity is also an important cue for your body to tell time.

It might be impossible to walk around all day if you work a desk job, but if you go for a daily walk and do a short workout every day, your circadian rhythm should still be noticeably strengthened.

Other implications of circadian rhythm…

As we’ve said, our brain is more wakeful and focused and more energetic in the morning (or at least it should be). That means that you should try to perform your most complex tasks, the ones that require the most brainpower and focus, in the morning. That’s the time of day when your brain is working at its best.

If you have a lot of routine, less mentally draining tasks (scanning documents, checking e-mail), then try to move those to the afternoon, when your brainpower has diminished.

In other words, try to do ‘deep work’ in the morning, and perform so called ‘shallow tasks’ later in the day. (here’s an explanation of what the terms ‘deep’ and ‘shallow’ work mean)

Not only will this allow you to get more done, it will also ensure that you’ll produce work of a much higher quality.

Now, there are always people who are going to say: ‘Oh, but this famous writer/musician/CEO always did his work in the afternoon, so in reality it doesn’t matter.’ or ‘I feel tired and unfocused in the morning, so this doesn’t apply to me’.

This may sound like a reasonable argument, but it really isn’t. If you have good habits and create a set time of day during which you work, of course it’s always going to be easier to get things done.

But if that person had made a habit of working earlier in the morning, and had a strong circadian rhythm, he’d probably be able to produce much better work and do even more.

And what if you think that you’re different and you’re ‘just not a morning person’? Well, it might be because you have terrible circadian habits.

Try to get a lot of light exposure during the day and significantly increase your activity level for a while. See what happens.

Lots of light + lots of activity = lots of well being and mental focus

Not only will you experience massively improved sleep, you’re also going to feel much more energetic, mentally focused and have a ton more willpower than you did before. All of which work wonders for being productive and getting things done.

Besides sleep and mental focus, there are other benefits to optimizing your schedule for your circadian rhythm. For example, people who lift weights in the afternoon are much stronger and have been shown to build much more muscle than those who workout before noon.

Having a strong circadian rhythm really makes an enormous difference, and that’s why it’s important to plan your daily activities in function of what your body is supposed to be doing.

Optimize your biology, and you’ll optimize your life

There are a lot of things you can do to improve your health, your focus and your productivity. Eat healthy, exercise, get ‘enough’ sleep. Quit Netflix and drop your e-mail addiction. (Use FocusMe)

But above all, one of the most important things you can and should do is try to optimize your circadian rhythm.

So give it a try: move more, get more light and you’re sure to get more done.

Signing off,


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