This is FiveMinuteFriday, The Importance of Sleep.
Welcome back to the SuperDataScience podcast, everybody. Super excited to have you back here on the show. In today’s episode, we’re going to talk about the importance of sleep. And why is that? Well, with this whole coronavirus pandemic being around, I’ve heard some very valuable information from a very reputable source A.K.A. my mother. And she says that in order to help your immune system be strong, you need to do, at the very least, these two very important things, and they are drink lots of water and get enough sleep.
And of course, there are other things that are important in this realm, but those are extremely important. I think we’ve all had the situation where you don’t get enough sleep, and you feel compromised in terms of your immune system, or you feel tired and just not productive or energized, or when we don’t get enough sleep, and we … Water, don’t get enough water, we feel dehydrated.
And so we decided to look into this further at SuperDataScience. We commissioned a study or an article that aggregates a lot of studies on the importance of sleep. You can find it at www.superdatascience.com/blogs, and it’s called Smarter Sleeping for Data Scientists. So if you ever want to check it out, it’s there. There’s a lot of links, a lot of interesting articles and research papers that you can drill in further, they all aggregate there. And there’s, of course, this blog that describes all these things.
And in today’s episode, we’re going to quickly dive into some of the most juicy takeaways, and if you ever want to go further, you can check out the article. So what are we going to talk about today are three main things: the amount of hours that you need to sleep, when you need to sleep, the timing of sleep, and naps. Are naps good or bad? So let’s check it out.
So first things first, the amount of hours that we need to be sleeping. There’s been quite a few studies. The first one we’re going to look at was published in the American Journal of Health Promotion. And in this study, they looked at almost 600,000 employed adults from multiple different industries ranging all different ages from 18 years old to 65 years old. So 600,000 people were part of the study. And they saw that the people with the highest productivity, who reported the highest productivity, were people who reported sleeping eight hours.
And an interesting thing they also found there was the relationship between sleep and productivity has a U-shaped curve, meaning that your optimal amount is eight. If you sleep less, then you’re going to be less productive. But on the other hand, if you sleep more, you’re also going to be less productive. How paradoxical is that?
Moreover, another study by the National Sleep Foundation found that there’s evidence linking too little sleep, less than six hours, or too much sleep, more than 10 hours, with cases of heart disease and obesity. So yet again, you don’t want to sleep too little. So, anything under six hours is too little. Anything over 10 hours is also too much. Of course, the exceptions here are if you’re doing it like a one off to catch up on your sleep deprivation or sleep dep, as they call it. But if you’re doing consistently over 10 hours, that could be a health risk.
On the other hand, the American Academy of Sleep didn’t find evidence that if you sleep more than nine hours at night then there is any risk to your health. But at the same time, they did find evidence that sleeping less than seven hours was associated with health issues such as diabetes, hypertension, heart disease, and stroke. And on that note, I should say that none of this is health advice, this is just a summary of the research that we found. Definitely talk to your health practitioner about all of these things and how they apply in your specific individual circumstances. And these are just the facts, these are just the findings, so you can make your own conclusions from here. But I think we agree, or at least the studies agree that the optimal amount of sleep is precisely eight hours, more or less. So, yeah, that’s the number of hours.
So the next question is when to sleep? And this is a very interesting question because we know that there are people who consider themselves night owls, there are people who consider themselves larks. And that some people prefer to work in the evening, some people work in the morning. For instance, I feel more creative in the evenings, but I feel more productive and energized in the mornings, if I start my morning right. And we are all different in that sense.
But here’s what we found when digging through all the research. First of all, melatonin. Melatonin is a hormone in your body that is produced by the pineal gland, it’s actually in your brain and it is only produced at night. So any kind of daylight will reduce the production of melatonin, and actually inhibit production of melatonin. And what do we need melatonin for? Well it is a hormone that makes you feel sleepy, you feel it’s time for bed. And that’s how our circadian rhythm works. By the way, an interesting fact I found on today for myself that circadian actually comes from two Latin words, circa meaning around and dian, meaning day. So it’s like going around the clock in the day.
So back to our podcast, so basically this hormone is produced only … and that part of your circadian rhythm when it’s nighttime, when you’re not getting daylight in, that triggers you to feel sleepy and actually go to sleep. That’s just something you need to be aware of, so if you go to bed at 2:00 AM, well, you’re going to be producing melatonin for that much less time.
And the second thing we need to look at is what is actually the function of sleep? There’s still a lot of ongoing research in this space. We still don’t know exactly what happens in the brain especially during sleep. But what we do know is that sleep acts as a sort of a maintenance function and it helps restore your brain, prepare it, like put everything in order to prepare it for the next day. And at the same time also we know that during sleep, a hormone called HGH, or the human growth hormone, is produced. And there was an interesting study back in 1986 showing that when they took 10 healthy male subjects and they isolated them from all kinds of cues like daylight and things like that, and from the circadian rhythm. And they first allowed them to sleep only at specifically scheduled sleep episodes. And on the other hand, later they allowed them to sleep whenever they wanted, and so create their own rhythms for sleep.
And so what they found was that the human growth hormone is better produced much … Like the spikes of human growth hormone are best when you’re sleeping when you’re supposed to be sleeping, rather than sleeping at random times, like creating your own schedule. And what that means is that your body restores, your brain and your body restores better if you sleep at the times you’re supposed to be sleeping. And ultimately, the human growth hormone not only helps you grow. Like if you’re young, then that that is required for you to grow. But also it restores your liver, your kidneys, and all sorts of your organs that need restoration over time. So, that’s another thing to keep in mind.
So basically when to sleep? Ideally, probably … There’s no conclusive evidence on this. The jury is still out in a way. So the best time probably is to sleep when it’s dark outside. But it’s up to you when you do sleep. It’s just something to be cautious of is to do it consciously rather than … It’s very easy, especially with these lockdown and quarantines, it’s very easy to fall into the trap of going to sleep later and later and later, staying up later, and basically waking up later, and to mess up your rhythm of your body and what you get, what the benefits are that you get from your sleep.
It’s certainly fine to go to bed late if you’re doing it consciously, if you know, “Okay, I’m going to bed at 2:00 AM. At 1:00 AM, I’m going to put on the red filter or the blue filter on my computer screen so I don’t see this blue light, so I feel that I’m prepared for sleep, I feel sleepier. Then I’ll sleep this many hours,” and so on. If you’re doing it consciously, you’re at a much greater advantage and in more control than if this is just happening to you. So, that’s probably the key takeaway from here. And of course, also keep in mind melatonin and human growth hormone.
And then, part three, naps. Are naps good or detrimental? Can they be detrimental? Well, the answer is both. Naps can be very good for you and naps can also be detrimental. So, there are three types of napping that you could be partaking in. Planned naps, when you are not feeling tired, but you’re using it as a precautionary measure to evade onset of sleepiness in the evening. Emergency napping, when you are suddenly tired and you want to combat dangerous levels of drowsiness. For example, when driving or operating heavy machinery. And habitual napping, that’s just taking the naps each time of the day, same time each day. And that’s typically after lunch for adults and very common for babies and young children.
So, there’s those three types of napping. And the research on napping shows, there’s studies including a study by NASA, show that a short nap, for example, in this study, it was like a 40 minute nap, can reduce performance lapses. For them, it was about by 34% at NASA. And decrease by a whopping 50% of the sleepiness that you feel in the evening. So, short naps, in this case, 40 minutes, can be very good.
But something to keep in mind with napping is that your full sleep cycle from REM, deep sleep, and light stages lasts about 90-110 minutes. So, that’s one cycle, and it goes again and again, and so on. So, one thing to be careful of is napping to the point where you’re in your deep sleep, and then being pulled out of that deep sleep. So, if you are in deep sleep during a nap and you get pulled out of it by an alarm or a colleague or whatever else is happening around you, you will feel actually worse. You’ll feel drowsy, you’ll feel groggy, you’ll feel sleepy. You’ll want more sleep because you’re exiting at the wrong time.
So, what you actually want to do, or what is recommended by the studies that we looked into is to grab a snippet of the superficial stages of your sleep, which happen in the first 20 minutes or so. And that will help you feel refreshed and alert and ready to keep going. And so, how do you do that? Well, there are apps for that. For instance, one that I really like is Calm. Calm.com, you can download it there. They’ve actually timed their napping music to about 60 … Not 60, about 26 minutes. And they say that’s the perfect time to sleep, to have a nap for. And there’s another app, Sleep Cycle, which allows you to monitor your … or create a model for your own individual sleep cycle patterns. And it’ll help you wake up in the right times during that sleep cycle. So, that’s another app you could check out.
Basically, the summary on naps is that they are great if you sleep the right amount of time, if you identify for yourself what’s a good amount of time. Or if you’re going to go more than that superficial sleep, whatever it is for you, then you’ve got to be prepared to sleep the whole cycle, which is like 90 minutes, without getting out of it. So, basically, if you’re getting out of it and you’re feeling groggy, then you’re doing something wrong and you can adjust it next time.
So, there we go, that’s the summary for sleep. Hours, eight hours. When to sleep? Probably it looks like most research says that it’s better to sleep when it’s dark outside. But if you want to do it in a different way, then just be conscious of how you do it. Don’t let yourself slip into that habit, especially while we’re in these lock downs, it’s very easy to slip into it without being aware of what we’re doing. And finally, naps. Naps are good if they are done also consciously, if you take just the superficial part of sleep to get refreshed, or you do the full sleep cycle. And there are apps for that, like Calm and Sleep Cycle.
So, there we go. That’s on the Importance of Sleep. Hopefully this is helpful and you got some interesting takeaways from that. If you’d like to see the study or the aggregation of literature that we’ve put together for you, you can check it out on the www.superdatascience.com/blog and you’ll find it there under Smarter Sleeping For Data Scientists.
Ultimately, we want to sleep a good … We want our sleep to be good so we can be productive, enjoy life, and create amazing things in our work as data scientists. On that note, stay healthy, sleep well, and I look forward to seeing you back here next time. Until then, happy analyzing.
