Sleep Cycles - When Is The Best Time To Go To Sleep?
A quality sleep is one of the crucial factors for proper functioning during the day. But sometimes it’s not that easy to have it. There’s a common misconception that long sleep equals good sleep. It certainly happened to you too, you went to bed ridiculously early so you can wake up in time for work and then you woke up even more tired. So, what’s the deal? We’re going to teach you more about sleep cycles.
Apparently, the length of the sleep is not the most important factor in quality of the sleep. Recently, someone created a convenient thing called sleep calculator. With the help of the sleep calculator we can calculate when we should hit the bed in order to wake up rested and ready for the day.
The basic principle sleep calculators work on are sleep cycles. Every sleep cycle is a period of around 90 minutes in which our mind goes through five stages of sleep. The first four stages make up our non-rapid eye movement (NREM) sleep, and the fifth stage is when rapid eye movement (REM) sleep occurs.
NREM sleep occurs during the first four stages, moving from light sleep in Stage 1 to very deep sleep in Stage 4. It’s very hard to wake up someone who’s in Stage 4 of sleep. During the first four stages there’s not much muscle activity and our eyes don’t move, but our muscles retain their ability to function.
In REM sleep, as the name suggests, we have a lot of rapid eye movement. This is the stage of sleep when most of dreams occur, so we believe that eye movements are related to the visual images of dreams. It’s not confirmed, though. Despite our eyes moving, the muscles that move our body are paralyzed. Other important muscles like heart and diaphragm still work normally.
So basically, it’s about calculating your sleep cycles, so you could wake up at the end of it. If you wake up in the middle of a sleep cycle you’ll feel tired, even if you slept longer.
How to calculate your sleep cycles?
Let’s give you an example. Need to make sure you’re awake and getting out of bed at 7am? Then you need to go to bed at either 9.46pm or 11.16pm. If you’re having a late night and you don’t fancy either of these, then 12.46am and 2.16am will also work.
The sleep calculator also includes the average of 14 minutes that takes people to naturally fall asleep, so it’s not a must to be in bed by that time.
To get up at 6am, you’re looking at a bedtime of 8.46pm, 10.16pm or even 11.46pm or – if you’re feeling like a real night owl – 1.16am.
Don’t need to get up super early to get to work on time? Have no fear. Here’s what time you need to go to bed for an 8am rise: 10.46pm, 12.16am, 1.46am or 3.16am.
You can even be more precise. If your ideal wake up time is, let’s say, 6:35, then your bed time would be 9.21pm, 10.51pm, 12.21am or 1.51am.
Duration of sleep phases
But it’s not that simple, to put it in 4 to 6 90-minute sleep cycles. Over the night the amount of time we spend in NREM and REM phases change. During the first 2-3 sleep cycles, we spend most of our time in deep NREM sleep (stages 3-4), whereas during the final 2-3 sleep cycles, we spend much more time in REM sleep accompanied by lighter NREM sleep. And not only that. Apparently, the duration of REM and NREM stages also depends on time of the day. Regardless of when you fall asleep, you’ll experience more NREM sleep in early hours of the night, and more REM in later hours and early morning.
Giving yourself a full sleep cycle (90 minutes) in the afternoon can help you memorize certain skill you’ve just learned, but for recovering from fatigue a 15-20 minute nap is ideal, since the further along you are in your sleep cycle, the harder it is to get over that grogginess you sometimes feel when you first wake up, which we call sleep inertia.
Some remote cultures are known to sleep in two stages: about six hours at night and a one and a half hour nap in the afternoon. This sleep schedule is similar to those Mediterranean cultures known for their mid-afternoon “siestas.” This type of sleep schedule may fit better with our circadian rhythms which tend to experience a drop around 2pm. You probably felt that energy drop after the lunch. Even some corporations began to implement the afternoon nap in their business strategies in order to capitalize on this new power nap trend. Power naps can reduce stress at work, so it’s no wonder they’re so popular.
Our sleep is consisted of several repeated sleep cycles, each of them containing five stages. For the optimal quality of your sleep, you should calculate the ideal time to go to bed, so you can wake up in the end of a sleep cycle. With time, the length of cycles may vary and the needed amount of sleep may change. If you find it more convenient, you can throw in an afternoon nap in your sleep cycle too.