Sleep has been a field of ongoing research for many years now. In is quantified, qualified, widely documented, discussed, argued about etc. Every sensible person in the world knows that they should sleep around 8 hours per day, and there are many guidelines out there, e.g. the ones from the U.S. National Health, Lung and Blood Institute.
For the last year and a half, I have been very concerned about how much I sleep. Since I got an activity tracker, I have realised that on the average I sleep less than the benchmark value of 8 hours.
The absolute majority of portable sleep-tracking devices aimed for both clinical and quotidian use contain an accelerometer inside.
Seriously, check out the last link if you are in search of a sleep device for self: it's a great read!
So, an accelerometer registers your acceleration along the three axes and then the relevant software translates the data into a one-dimensional continuous variable representing activity counts. Based on specific algorithms (e.g. this one), the ability of an accelerometer to track even the tiniest motions and the supposition that when you sleep you don't move, the software classfies your time in bed into periods when you are asleep and when you are awake. The latter is called wake after sleep onset (WASO). The time during which you fall asleep is referred to as the sleep latency. When your portable monitoring device says that you have slept 7 hours it means the time you were asleep, i.e. the time in bed minus WASO minus sleep latency.
You normally also get to know your sleep efficiency, i.e. the percentage that the time you have slept makes up from your total time in bed or from your goal if you are aiming for a specific sleep time.
This efficiency measure is one of the ways to look onto the quality of sleep.
There is a huge body of scientific research that considers sleep quality: 6246 records on Pubmed as of today. Quality of sleep is something that is conceptually simple and complex at the same time, and, to my knowledge, there exist many different and no ultimate ways to measure and report on it.
Three main directions to approach quality of sleep can be outlined. The first one is by mere asking. You can address a respondent with a question about how well they have slept. You can take it one step further and suggest that they rate the quality of their sleep on some scale. In order to boost the validity of your judgement, you can ask them to do so for several days in a row (for example, seven) - and thus you will come up with what is called a sleep diary.
The second way is to employ the renown Pittsburgh Sleep Quality Index (PSQI). This is a questionnaire-based measure developed by the researchers of the University of Pittsburg, and it has been extensively used in research (1680 records on Pubmed by today). The index's values range from "poor" to "good", and various sleep parameters across several domains are used along the way, including: subjective sleep quality, sleep latency, use of sleep medication and others. In a relevant questionnaire, a subject should give answers to all questions based on what they think that applies to the majority of days during the month prior to questioning. It is a highly subjective questionnaire and index, and this is what it is sometimes criticised for.
The third manner to track sleep quality is to use a quantitative objective measure of sleep efficiency mentioned above.
Independently from the way how you measure the quality of sleep, it is obvious that getting quality sleep every night or at least most of the nights is very important for well-being of practically everyone.
The fact that sleep affects performance is soundly backed by scientific evidence, and there is no wonder that articles on how to boost your sleep quality appear in places like Yahoo! Finance. People I am friends with would even purchase blue light blocking glasses to wear them in the evening - the blue light allegedly (I have never checked) shuts down melatonine production in humans.
It is naturally up to you how far you should go in controlling your performance in sleep. I have worn both commercial and professional devices, and I can say that wearing a tracker makes you think more about how much you sleep and move. This is not necessarily a good thing and, depending on your mindset, it can make you upset or anxious .
Anyway, self-awareness is a good thing, and if you don't want to engage yourself in wearing a monitor, you can keep a sleep diary for a while of even compute the value of the Pittsburgh Sleep Quality Index for yourself.
For the last year and a half, I have been very concerned about how much I sleep. Since I got an activity tracker, I have realised that on the average I sleep less than the benchmark value of 8 hours.
The absolute majority of portable sleep-tracking devices aimed for both clinical and quotidian use contain an accelerometer inside.
Seriously, check out the last link if you are in search of a sleep device for self: it's a great read!
So, an accelerometer registers your acceleration along the three axes and then the relevant software translates the data into a one-dimensional continuous variable representing activity counts. Based on specific algorithms (e.g. this one), the ability of an accelerometer to track even the tiniest motions and the supposition that when you sleep you don't move, the software classfies your time in bed into periods when you are asleep and when you are awake. The latter is called wake after sleep onset (WASO). The time during which you fall asleep is referred to as the sleep latency. When your portable monitoring device says that you have slept 7 hours it means the time you were asleep, i.e. the time in bed minus WASO minus sleep latency.
You normally also get to know your sleep efficiency, i.e. the percentage that the time you have slept makes up from your total time in bed or from your goal if you are aiming for a specific sleep time.
This efficiency measure is one of the ways to look onto the quality of sleep.
There is a huge body of scientific research that considers sleep quality: 6246 records on Pubmed as of today. Quality of sleep is something that is conceptually simple and complex at the same time, and, to my knowledge, there exist many different and no ultimate ways to measure and report on it.
Three main directions to approach quality of sleep can be outlined. The first one is by mere asking. You can address a respondent with a question about how well they have slept. You can take it one step further and suggest that they rate the quality of their sleep on some scale. In order to boost the validity of your judgement, you can ask them to do so for several days in a row (for example, seven) - and thus you will come up with what is called a sleep diary.
The second way is to employ the renown Pittsburgh Sleep Quality Index (PSQI). This is a questionnaire-based measure developed by the researchers of the University of Pittsburg, and it has been extensively used in research (1680 records on Pubmed by today). The index's values range from "poor" to "good", and various sleep parameters across several domains are used along the way, including: subjective sleep quality, sleep latency, use of sleep medication and others. In a relevant questionnaire, a subject should give answers to all questions based on what they think that applies to the majority of days during the month prior to questioning. It is a highly subjective questionnaire and index, and this is what it is sometimes criticised for.
The third manner to track sleep quality is to use a quantitative objective measure of sleep efficiency mentioned above.
Independently from the way how you measure the quality of sleep, it is obvious that getting quality sleep every night or at least most of the nights is very important for well-being of practically everyone.
The fact that sleep affects performance is soundly backed by scientific evidence, and there is no wonder that articles on how to boost your sleep quality appear in places like Yahoo! Finance. People I am friends with would even purchase blue light blocking glasses to wear them in the evening - the blue light allegedly (I have never checked) shuts down melatonine production in humans.
It is naturally up to you how far you should go in controlling your performance in sleep. I have worn both commercial and professional devices, and I can say that wearing a tracker makes you think more about how much you sleep and move. This is not necessarily a good thing and, depending on your mindset, it can make you upset or anxious .
Anyway, self-awareness is a good thing, and if you don't want to engage yourself in wearing a monitor, you can keep a sleep diary for a while of even compute the value of the Pittsburgh Sleep Quality Index for yourself.
