What is the circadian rhythm? | The influence of modern life | The effect of light | Timing caffeine | Good sleep hygiene | Eat at set times
| Exercise | Take aways
Maybe you know the feeling: You lie awake in bed, all too aware that the clock is ticking into the wee hours of the morning. Or maybe you struggle to wake up in the morning and feel groggy for hours after getting up. Sleepless nights are incredibly frustrating, but there are many things you can do to help yourself fall asleep, stay asleep and wake up rested—it all starts with your circadian rhythm.
What is the circadian rhythm?
The circadian rhythm is your body's internal clock that regulates your daily schedule of sleep and wake and repeats itself every 24 hours. Every organ and cell in your body has its own internal clock. [*] While most people will notice the effect of the circadian rhythm on their sleep pattern, the circadian rhythms affect many important functions in our bodies, such as:
Metabolism and weight
- Mental health
- Hormone release
- Eating habits
- Body temperature
Usually environmental factors influence the circadian rhythm, such as light and dark, shift work or jet lag. Certain genes can also impact our biological clocks. [*]
The influence of modern life
We used to get up when the sun was up and go to bed when the sun was down. The invention of the light bulb made it a lot easier to stay awake when it was dark outside. Add to that the bright blue screens, computers, tablets, TVs that we have available to us 24 hours a day these days. All of which are major disruptors of our sleep-wake cycle. [*]
But it is not only light that disrupts our circadian rhythms. Because circadian rhythms play an important role in metabolism, eating habits and digestion, the timing of food is crucial. [*] [*] With 24/7 access to food via meal delivery or a refrigerator, this disrupts our internal clock even more. Although the world we live in today makes it a challenge to get our circadian rhythms working as they should, it is not impossible. Here's how to optimize it!
The effect of light on your Circadian Rhythm
Light has such a profound effect on your circadian rhythm that a two- or three-day camping trip, without access to electronics or even watches (where you let the sun dictate when you should get up and when you should go to sleep) showed a great effect on the sleep-wake cycle. Even so effective, that in this way your entire cycle could be reset. [*]
There are also things you can do at home on a daily basis. Sitting or walking outside in daylight for half an hour to an hour during the first half of the day naturally inhibits melatonin. You can even sit in front of a glass window while enjoying your breakfast. It doesn't have to be sunny, either. [*]
Equally important is to optimize indoor light. Even though you may not be able to go outside much, try to get as much natural light in during the day as possible by working and living in a room with large windows. [*]
As mentioned above, bright natural blue light is very effective at naturally interrupting melatonin production and sending a signal to our brains to be more alert and functional. [*]
However, you can imagine wanting the opposite at night, when you are about to wind down. [*]
To allow the sleep hormone melatonin to rise naturally, you need to block blue light around 8-9 PM. That's why it's so important to avoid blue light at night.
A strategy you can adopt is a 'night switch' on your computer and other devices. The built-in 'night switch' is actually perfect to use during the day, to avoid unnaturally harsh light. For at night, there is an app for your computer screen called ‘Iris’, which goes far beyond the built-in ‘night-switch’ in blocking blue light. If you want to take it to the next level, you can turn your smartphone screen to red with this hack (also much more effective than the ‘night-switch’ option). Of course, the TV cannot be forgotten! The 'DriftTV' box helps you remove the harmful blue light from your TV screen. Besides screens, install red light bulbs, salt lamps, candlelight or even wear blue blocking glasses.
All of these tactics may or may not help you raise melatonin, but in any case, it sends a signal to your brain that it's time to sleep. Alternatively, a sleep supplement containing melatonin and 5-HTP could be an option. [*]
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Caffeine can be a major disruptor of sleep. Caffeine resets the body's internal clock by delaying a rise in melatonin. Like avoiding bright lights at night, timing caffeine is one of the quick wins to optimize sleep, if you do it right. Here are some simple coffee take-aways to keep your circadian rhythm in sync:
- Six hours after you consume caffeine, half of it is still in your body. It can take up to 10 hours to completely remove caffeine from your bloodstream—making it very difficult to sleep at night if you consume caffeine too late in the day. [*]
- And did you know that some people are naturally slow or fast metabolizers of caffeine? In people who metabolize caffeine at a slower rate, it stays in the body longer. For them it is extra relevant to stop drinking coffee in time. Enjoy your coffee until about 2 p.m. to improve your sleep quality and energy the next day. [*]
- People who don't have a 9 to 5 job and have to perform at unusual times can benefit from the alertness that coffee provides. You can use coffee to your advantage if you have to work early in the morning or to be alert in the car. [*]
Good sleep hygiene
Sleep hygiene is another important factor for optimal sleep. Some tips you can try are:
- Be consistent in going to bed at the same time every night and getting up at the same time every morning, including on weekends.
- Be sure your bedroom is quiet, dark, and has a pleasant temperature. [*]
- Remove smartphones, a TV, a computer and other electronic devices from the bedroom.
- Use your bedroom only for sleeping, reading and lovemaking—never for working. This allows your brain to associate the bedroom with a relaxing space.
Eat at set times
With 8 hours of sleep, the brain repairs itself. Just as the brain is shut off from outside stimuli during sleep, so too must the body, the cells, the organs, be disconnected from external stimuli. One of those is food. For example: when we eat, it quickly changes the release of many hormones.
But if the brain only needs 6-8 hours of sleep to recover, why does the body need 12-14 hours without food? The answer is: the body needs at least 5 hours to digest the food. This means that if you eat at 6 p.m., your stomach is still working at 11 p.m. or later. After that, your body finally gets a chance to recover and reset. [*] If food is taken too close to bedtime - your body may not get the full 100% rest it needs. [*]
There is also a physical component to why it is better to let your body digest the food before it goes to sleep. Your body is meant to digest in a more upright position, not lying down. Because it takes 5 hours or more to digest, it's most ideal to stop eating at least 3 hours beforehand, but it can be as much as 5 hours. [*]
Being physically active during the day can help you fall asleep more easily at night. You may have already experienced that if you had an active day outside, you fell asleep faster.
However, the timing of your exercise matters to your sleep quality.
For example, aerobic exercise in the morning or afternoon stimulates an earlier release of melatonin and shifts the circadian rhythm forward. [*]
When to exercise also depends on your sleep chronotype. For some people, exercise within a few hours before bedtime can cause problems falling asleep.
Research on male soccer players has shown that evening exercise can negatively affect sleep quality in early risers, but not in night owls. This may be one reason why some people have no trouble exercising in the evening, while others have trouble falling asleep afterwards. [*] The solution is to try it yourself.
To fall asleep faster and sleep better, it's best to take in as much natural light as possible during the day. At night it's better to block out artificial light. Avoid large meals and even snacks at least three hours before bedtime. Be careful about drinking caffeine after 2 p.m. and try to avoid alcohol before bedtime.
Get your sleep hygiene in order by going to bed at the same time every night and getting up at the same time every morning, including weekends. Make sure your bedroom is quiet, dark, relaxing and has a pleasant temperature. Get some physical activity. If you are physically active during the day, you may fall asleep more easily at night.
If the above still doesn't help enough, a sleep supplement with a small dose of melatonin and 5-HTP may be for you.
Is it all still too overwhelming for you? Circadian Life is an app that reminds you at set times throughout the day when to get up according to your circadian rhythm. It also tells you when to exercise, when to eat, when to avoid blue light, when to relax and when to sleep. You can download the app here.