The human body requires certain hours of sleep to function properly. When your body is not sleeping at its optimum time, it will suffer from various health problems such as fatigue, depression, weight gain or even death. For example if you are working late into the night and don’t get enough sleep during the day, you may have difficulty concentrating at work and perform poorly in your job. If you are going out after midnight, you may experience symptoms like nausea, headaches and dizziness.
As humans we evolved to live in a world where sunlight was available 24/7. However, modern life has changed our lifestyle to the point where most of us spend only part of our lives outdoors. Our bodies need daylight to function properly. This means that we need to go outside at least once every few hours to take care of basic needs such as eating, drinking water and so forth.
However, when we do go outside, we tend to stay indoors for long periods of time. Even if we are not actively doing anything (like reading a book), our brains still need some amount of time to wake up from deep sleep before being able to focus fully on what’s happening around them. When we go straight from being outdoors to being indoors, our brain has to re-adjust its internal body clock.
What this means is that, in the long-term, it’s better for your overall health if you take short breaks outside during the day rather than staying inside for long periods of time.
However, this does not mean you should go directly from being indoor to being outdoor or else you may experience “day blindness” where your eyes are not used to processing large amounts of light. If this is the case, you may find yourself experiencing temporary symptoms such as dizziness, nausea and headaches.
The best thing to do is to expose yourself to sunlight or any other bright light source (such as an ordinary incandescent bulb) for a few minutes before going outside. The time you spend looking at the light source depends on how long you’ve been staying indoors. The longer the period of time you’ve been indoors, the more time you should allow yourself to “wake up” before going outside.
In fact, it’s best to expose yourself to light sources of a particular color before going outdoors because your eyes will have to quickly adjust from a lower color spectrum (such as red and yellow) to a higher one (such as blue and green). This can be achieved by looking at a plain white sheet of paper or any other white flat surface.
For example, if you’re inside for two hours, you should look at a light source for at least twenty minutes before going outside. If you’re inside for eight hours, you should look at a light source for at least one hour before going outside. You do not need to stare at the light source the entire time. You can blink and look away from it so as to not cause damage to your eyes. However, you should stay within the vicinity of the light source (e.g.
if you look at a light source from two feet away, you should continue to look at a surface within two feet of that light source).
Now, for those who work the night shift (such as doctors and nurses), the procedure is a little different. Since your body has gotten used to staying up during the night and sleeping during the day, going outside during the day may make you feel sleepy. You may find yourself yawning a lot or experiencing “night lag”. To avoid this, you should restrict the amount of time you spend outside during the day.
If you’re only going to be outside for less than thirty minutes then it should be fine to go outside directly. If you’re going to be outside for more than thirty minutes, you should expose yourself to a light source first. The same amount of time as mentioned in the section before applies here as well. So if you’re going to be outside for two hours, you should still look at a light source for at least twenty minutes before going outside.
If you work the night shift and plan on going straight home after work, it’s best to arrive home during the day so you can go outside during the day and then sleep during the night when you get home. This will help your body adjust to the schedule change.
Of course, if you can’t do this (such as if your place of work has a night shift and you want to arrive home during the day), you may do it in sections. For example, if you work an eight hour night shift and want to arrive home during the day, when you get to the four hour mark, you should expose yourself to a light source for at least twenty minutes before going home. If you work an eight hour night shift and want to arrive home during the night, when you get to the four hour mark, you should go home during the day. Once inside your home, you can then go to sleep so that you’ll wake up at night and be able to stay up during the night.
Sources & references used in this article:
Effects of chronotype and time of day on mood responses to CrossFit training by M Sławińska, M Stolarski… – Chronobiology …, 2019 – Taylor & Francis
Urine specific gravity in exercisers prior to physical training by EA Stover, HJ Petrie, D Passe… – Applied physiology …, 2006 – NRC Research Press
Effect of time of day on sustained postexercise vasodilation following small muscle-mass exercise in humans by LC Brito, MR Ely, DC Sieck, JE Mangum… – Frontiers in …, 2019 – ncbi.nlm.nih.gov
The Effects of Time of Day on Resistance Exercise Workout Responses by HN Husmer – 2013 – opencommons.uconn.edu