Is 6 hours sleep a night enough? If somebody offered you a pill that increased your concentration, lowered your blood pressure, reduced your risk of disease and improved your problem-solving, decision making and learning with no negative side effects, presumably you’d all take it? Well, there is one downside, it takes up 8 hours of your day in order to get the benefits. The big question each of us faces is how much sleep is enough and how do we make sure we get it.

Studies show a clear positive correlation between the level of sleep achieved and income earnt. This is likely due to the productivity and other mental benefits associated with improved sleep quality. However, those earning truly exceptional incomes often do so at the expense of sleep.

In recent weeks, here on The Progression Playbook we have been almost solely focused on the granular details of achieving financial independence such as getting a LISA, signing up to an investment platform, how much to contribute to your pension and so on. In today’s post, we’re going to pivot back to the big picture and in particular, take a look at the important role sleep plays in achieving our goals and in our wider lives.

Is 6 hours sleep a night enough?

For most people, 6 hours sleep a night is simply not enough and consistently low sleep could lead to poor health consequences including problems with memory, focus and the immune system. The National Sleep Foundation recommends an average of 8 hours of sleep per night for an adult.

Almost every authority on sleep out there says 6 hours of sleep is simply not enough. The problem is, for people with busy lives, the general consensus seems to be you can get away with 6 hours and still live a perfectly healthy life.

However, the research doesn’t seem to support this, the National Sleep Foundation suggests 7-9 hours per night (research linked here) and a multitude of other research out there links low daily sleep with serious illness.

A few examples include:

  • This study, which links undersleeping to an increased risk of diabetes.
  • This 2011 study linking poor quality sleep to an increased risk of stroke.
  • This 2010 study which goes as far to link undersleep to an increased risk of early death.

So clearly the downsides of undersleeping are clear but what’s also worth noting is just how beneficial getting the right amount of sleep consistently can be.

sleeping 6 hours a night

What is the Circadian rhythm and what are sleeping chronotypes

The first big thing to understand when it comes to your sleep is the circadian rhythm. This is essentially an internal process that tells your brain when you should be asleep (the night) and awake (the day) over the course of a 24 hour period.

Whilst this is usually guided by the light of day and the dark of night, experiments have shown that the circadian rhythm works without these natural queues. For example, certain flowers open and close in line with a circadian rhythm and in experiments where these plants are left in a dark room for a number of days, the flowers will still open and close over the course of 24 hours thanks to their circadian rhythm.

Matthew Walker’s excellent book ‘Why We Sleep‘ introduces the concepts of morning larks and night owls whereby humans fall into two broad categories of the circadian rhythm. As the names suggest, morning larks prefer to wake up on average at 6:30 am and night owls prefer to wake up on average at 10:30 am.

Now clearly in the current world, waking up at 10:30 am isn’t practical for either school or employment and it should be made clear, the night-owls 2:30 am – 10:30 am sleeping period is the time of day they are most naturally suited to being asleep but not necessarily the time they are actually asleep.

As you can imagine, this can have serious consequences in peoples day to day lives. If you are the type of person with a night-owl sleeping chronotype which is best suited to falling asleep at 2:30 am but work a job that means you have to wake up at 6:30 am, you may be left in the desperate situation of only being able to achieve 4 hours sleep a night which, as shown above, is hugely damaging for your health.

Nowhere is this issue more clear than with school-children and in particular teenagers. In Matthew Walker’s book ‘Why We Sleep’, he explains that as children become teenagers, hormonal changes change the circadian rhythm meaning teenagers get tired later in the day and end up sleeping a few hours later than they would have as a child.

Due to schools in the UK typically starting at 9 am, teenagers are still required to wake up at the same time as they did when they were children, only now they are falling asleep much later. The obvious result is significantly less sleep each night and all of the issues around memory and concentration that follows.

What starts to become clear is that the education system and society at large don’t consider the latest scientific research on sleep and react by optimising start-times for the pupils.

Why the “I can get by on four hours a night” crowd are lying to themselves

Every few months, I hear a story of a prominent figure attributing their success to only sleeping a few hours a night and that all of their accomplishments are made simply because they have so much extra time devoted to working.

This article suggests Donald Trump only sleeps four hours a night (even pre-Presidency), whilst Oprah claims she can “function very well on 5 hours sleep per night” but the science doesn’t seem to support either of these claims.

The reason behind this is that the real benefit-inducing parts of sleep known as REM and NREM sleep are missed when we don’t sleep a full cycle.

So whilst it is true that if you slept 3 fewer hours a night you would have more time to be productive, this isn’t sustainable over the long term. Not only will your health start to suffer, but your levels of concentration and memory will also almost certainly be impaired throughout the day which will make this a zero-sum game.

When I used to work long hours in my old job as a Big 4 auditor, I would at certain times throughout the year find myself still working at 11 or 12 at night. A question I would ask myself is “is the work I’m getting done tonight worth the reduced productivity tomorrow?” and I always seemed to come to the same conclusion; that it wasn’t.

For example, if the two options were to a) work 9 hours in a day and finish at 7 pm and be able to work at 100% productivity all day or b) work 13 hours in a day and the final 4 hours of each day were at 50% productivity and it meant the next day was all at 75% productivity, it quickly becomes clear which yields the more ‘productive work’ over the course of a week.

Moving away from the ‘I’ll sleep when I’m dead” mindset

Most of us will have heard the common maxim “I’ll sleep when I’m dead” which is basically a brazen way of saying that sleep is not a priority right now.

The problem, and grim irony, of this statement, is that sleep has to be a priority or as this study suggests – death may come a lot sooner than expected. The notion that in order to achieve your goals quickly you should forego sleep is deeply flawed. This might work over a day or two, but over the long run, you’d almost certainly be better served making sure you get a strong, consistent level of sleep so that your brain is in peak condition to work towards your goals each day.

How lack of sleep may impact your personal finance goals

Whilst it may seem strange reading an article based on sleep whilst on a website dedicated to financial independence – the reason I have written this post is that I see poor health as the biggest threat to a prosperous life post-retirement. I also believe that staying healthy through high-quality sleep will help me to achieve these goals faster as my brain will be more able to operate as it should.

The first obvious way in which our personal finance is impacted by a lack of sleep is the costs associated with poor health. Although we have free health services in this country, it would be naive to ignore the more hidden costs of poor health such as over-the-counter medications.

Further still, lack of sleep has been linked to poor concentration and decision making. For those of us chasing financial independence, we want to be fully in control of our decision making particularly when it comes to investing our money. Poor investment decisions based on emotion are, I would imagine, all the more common when we are tired and not thinking with 100% clarity.

On this blog, I’d usually warn you about the pitfalls of consumerism and how each material item you buy is another few weeks or months you may have to wait to become financially independent. However, due to the overwhelming evidence in support of sleep, I put this advice to one side when it comes to buying the following items:

  • Bed frame
  • Mattress
  • Bedsheets / duvet / pillows
  • Blackout blinds
  • Fans or other air cooling system

All of these things, in my opinion, are worth spending on. If you’re going to spend excessively on anything, it may as well be on things that you will be using for approximately a third of your life whilst asleep. Buying the highest quality versions of these products that you can afford will provide an incredible return over the long term simply through the health benefits proper sleep can provide.

The impacts of sleep on your general health

I’ve alluded to the generally harmful impacts of a lack of sleep on your health in terms of potentially life-threatening diseases. However, poor sleep can have much more common effects on your health than that, even if not quite so deadly.

The first one that springs to mind is over-eating, the science suggests that sleep deprivation leads to increased hunger which in turn causes all of the negative health impacts of poor nutrition and in severe cases, obesity. Large scale studies such as this one show that adults are more likely to be overweight or obese if they are sleep deprived.

There’s also widespread information out there linking a lack of sleep with poor school performance. This article suggests children’s education starts to suffer due to poor focus and memory problems.

Hopefully, the importance of high-quality, consistent sleep is becoming clear given the perilous impacts disrupted sleep has on important areas of life like nutrition and education.

10 quick tips for better sleep

So now onto the good stuff, my top tips on how to improve your sleep based entirely on scientific research:

Tip #1 – Give yourself a sleep opportunity of 8.5 hours every night

The single most important thing you can do is to give yourself a sleep opportunity of 8.5 hours a night. This means that you are in bed, in the dark ready to sleep for this full period. Even if you don’t manage to fall asleep straight away or wake up in the night, you will likely be able to achieve at least 7 hours of full sleep which is the bare minimum you should be shooting for.

Tip #2 – go to bed and wake up at the same time every day

The best thing you can do to maximise the quality of your sleep is to wake up and go to bed at the same time each day, even on the weekends. Getting into this routine not only helps you to stay consistent with tip #1 above but also syncs with your circadian rhythm. If you give tips 1 and 2 a try together for the next week, I’d bet you will feel far less tired day-to-day even if you ignored all of the tips below.

Tip #3 – invest in your sleep

On this blog, I’d usually recommend frugality and not making unnecessary purchases but when it comes to your sleep, purchasing a high-quality mattress is something that’s definitely worth splashing out on. Not only will you be lying on this mattress for 8 hours a day but it could also last you over a decade so this isn’t something to skimp on.

Tip #4 – get the darkness of the room right

Similar to the above, investing in black-out blinds or curtains may be a worthwhile purchase. To optimise sleep, you need a dark room and even small changes like covering up TV lights or LED alarm clocks are worth making.

Tip #5 – get the temperature of the room right

Sleep scientists tell us that the optimal temperature to sleep at is 65 degrees Fahrenheit (or 18.3 degrees celsius) which is much cooler than the average in-home temperature. Therefore, to improve your sleep consider investing in air conditioning or a fan or simply by leaving the window open.

Tip #6 – Be sensible with caffeine

Science tells us that caffeine blocks the sleep hormone but what’s worse is the length of time caffeine stays in your system. The quarter-life of caffeine is 12 hours which means drinking caffeine at any point after lunch is almost certainly a bad idea for your sleep.

Tip #7 – get your smartphone in order with sleep in mind

Few things are as damaging for your sleep as your smartphone – read the subheading below for my advice on how to best mitigate this problem.

Tip #8 – avoid exercise just before bed

Generally speaking, exercising on a regular basis is beneficial for sleep. However, exercising within a couple of hours of sleeping raises your heart rate and may actually prevent sleep.

Tip #9 – consider relaxing before bed with a herbal tea

Drinking herbal tea before bed can help your body to relax. Just make sure it doesn’t have any caffeine included. Using a magnesium supplement can also aid sleep quality.

Tip #10 – if for any reason you can’t sleep, get up and do something relaxing

When most people can’t sleep, they lie there and hope to eventually drift off. However, this may not be the best way. Getting out of bed and doing something relaxing like reading (not on a phone screen) and then returning to bed when feeling tired is more likely to help you drift off.

How to optimise your phone to allow for better sleep

Until recently, I would often spend my final hour before sleeping on my phone, either browsing social media or reading on the Kindle app. The problem is both the stimulation of using these apps plus the harmful impacts of ‘blue-light’ are not conducive to a good night’s sleep.

Due to the addictive power of smartphones, I have found that willpower alone is not enough to prevent me from using my phone prior to bed and therefore sabotaging my own sleep. Because of this, I’ve tweaked a few key settings on my phone with this in mind:

  1. Turn night shift on 4 hours before you sleep. On most smartphones, there is now an option to turn on night-shift which shifts the colours of your phone to the warmer end of the colour spectrum which reduces the level of ‘blue-light’ emitted. After a few days, this shift is barely noticeable and I have found that making this change as long before I sleep as possible has helped improve my sleep quality.
  2. Leave your phone in another room or at least not right next to your head while sleeping. If you’re anything like me, whenever you can’t sleep you may turn for your phone. I have found that leaving my phone on the dresser on the other side of the room (rather than on my bedside table) has put a stop to this habit and has completely removed the poor habit of scrolling through my phone for hours whilst in bed.
  3. Ban access to certain apps at certain times of the day. This one’s a bit dramatic but can be effective. If you have identified that at 11.30 pm every day you like to sit in bed and scroll through Instagram – you may consider changing the access controls on your phone to ban access to Instagram between the hours of 11.30 pm and 6 am for example.
  4. Use your phone’s features to set a bedtime and wake-up time that’s the same each day. Linked to the point above which states that waking up and going to sleep at the same time every single day is one of the best ways to improve your sleep quality, this is one area where your smart-phone can benefit your sleep. Apple’s ‘bedtime’ feature within the ‘clock’ app is particularly good for this.

How to strike a good balance between sleeping, working and fun

The most common reason for poor sleep is poor sleep hygiene, i.e. not getting the conditions for sleep such as temperature, time of day and level of darkness correct. This aside, the biggest obstacle to consistently sleeping 7-9 hours a night is the conscious choice some people make to forego sleep in favour of social activities or working late which is something I am guilty of myself.

In my opinion, the optimum solution is to give yourself an 8.5-hour sleep opportunity whilst implementing the 10 tips for a better sleep above which should allow you to comfortably achieve 7 hours of actual sleep time at the very minimum. This allows you another 15.5 hours in the day to use up as you please, safe in the knowledge that your health and mental functioning isn’t being hampered by your sleeping habits.

Clearly, this isn’t realistic for some people who will at times prioritise late evenings at work or nights out drinking above sleep which is, of course, every individual’s own choice. Achieving the recommended 7-9 hours of sleep per night on a consistent basis will, in my opinion, provide you with a far superior return in the long-term than working late or partying late ever could but as with all things, a good balance needs to be struck.


My interest in sleep was ignited after reading Matthew Walker’s amazing book ‘Why We Sleep‘ which I’ve linked throughout this post for anyone who wants to pick up a copy. I also found this book so interesting it made the ‘TPP recommends‘ page of this website which I’d suggest checking out if you haven’t done so already.

Some of you may find yourself a little confused about why you have just read a 3000-word blog post on sleeping (thanks if you have made it all the way to the end) within a personal finance blog. My response to that is two-fold – achieving financial independence at a young age is a difficult thing to do and regardless of how many resources we read and practical saving and investing steps we take, if we don’t get the big-picture life basics like sleep right, everything else becomes far more of a struggle.

The second part of the answer is this; once I achieve financial independence, I want to be able to live exactly on my terms. The biggest threat to that is poor health which is something proper sleep can help combat.

Let me know if you have any sleeping tips you’d add to my 10 above in the comments!

As always, please remember I am an Accountant, but not your Accountant. In this post (and all of my others) I share information and oftentimes give anecdotes about what has worked well for me. However, I do not know your personal financial situation and so do not offer individual financial advice. If you are unsure about a particular financial subject, please hire a qualified financial advisor to guide you.

This article has been written by Luke Girling, ACA – a qualified Accountant and personal finance enthusiast in the UK. Please visit my About page for more information. To verify my ACA credentials – please search for my name at the ICAEW member finder. To get in touch with questions or ideas for future posts, please comment below or contact me here.