This article is inspired by Prof Matthew Walker. If you haven’t read ‘Why we need sleep’ I’d recommend it!
Do We Let Sleeping Dogs Lie?
1 Nov 19
“Get some head down lads, it’s 0100 now, reveille 0530 for weapons at 0900”
Sleep deprivation is often used as a military training aide to make a situation more arduous. It is also a natural by-product of a fast paced, well connected work force. Unfortunately, it has an extremely negative impact on disease prevention, physical function and mental performance.
This aim of this article is to highlight the benefits and mechanisms of sleep and identify the risk factors associated with reduced sleep.
“Start with why”
Sleep is vital for all animals. It helps us repair and restore our organ systems including our muscles, immune systems, and various other hormones. Without sleep we will simply not function.
There are two things that ensure we sleep; the Circadian Rhythm and a sleep pressure which builds in our brain telling us it is time to sleep. The Circadian Rhythm is regulated by melatonin; it is your body clock and takes time to adjust to time differences when travelling.
Sleep pressure or a sleep debt is caused by the buildup of a chemical named adenosine. It is a chemical which rises through the waking day and is depleted during sleep. It is like a pressure which builds up in the brain. Caffeine suppresses this pressure but only for a certain period of time, which is why you can stop the feeling of tiredness but only for a few hours before it hits you like a ton of bricks.
Types of sleep
Your body needs two types of sleep: Non-rapid eye movement (NREM) and rapid eye movement (REM).
NREM is the period of deep sleep that you need to feel refreshed in the morning. It occurs in longer periods during the first half of the night. Your heart rate and breathing slow to their lowest levels during this type of sleep. Your muscles tend to relax and it will be obvious to anyone looking at you that you are out for the count. Brain waves will become slower during this type of sleep.
REM sleep, first occurs about 90 minutes after falling asleep. Your eyes will move rapidly from side to side behind your closed eyelids. Your breathing will become faster and irregular, and your heart rate and blood pressure increase to near waking levels. It is during REM sleep that you do most of your dreaming. Your muscles will become temporarily paralysed during this period of sleep (this is thought to stop you from sleep walking). As you age, you spend less of your time in REM sleep. It is thought that memory consolidation probably requires both non-REM and REM sleep. This is perhaps why people get more forgetful as they get older.
So what kind of sleeper are you?
- A night owl
- An early bird
- An inbetweener
Having people alert at different times will give us an advantage in the hostile environment. One theory is that having people more alert at different times of a 24hr period was an evolutionary advantage for a tribe, allowing someone to always be on watch for predators or enemies. Indeed, if we have a natural evolutionary stag rota, perhaps troops could choose when they went on stag? Stand by for 0500 – 0600!
Many people work more efficiently in the evenings whilst others get the majority of their work done in the morning. The same also applies to physical exercise, with better physical training being conducted at the optimal time in their Circadian Rhythm. The Armed Forces tend to have one timing for all, but perhaps we would see increased performance, productivity and efficiency if we allowed people to choose their own timings, when it is feasible to do so in the working week. Could we give service personnel a little more autonomy in their sleeping and working timetable?
“But I’ve got by on 4hrs sleep for years…”
There is a very small percentage of the world that can get by on minimal sleep. Less than 1% of the population is able to survive on six hours of sleep and show minimal impairment with the BHLHE41 gene.
It is thought that good old Maggie Thatcher had this gene. However the majority of people not getting enough sleep will not be reaching their full potential and will be a prime candidate for a number of health issues…
The ticking health bomb…
It is appreciated that in the Armed Forces the mission and nature of essential training requirements will occasionally limit a person’s ability to optimally sleep. However, as an organisation if we fail to educate service personnel on the health risks of not sleeping when the situation allows, we will expose our troops to a number of health conditions:
- Obesity- The reduced leptin in your system will mean that you feel less full, you will have an increased appetite, and you will feel lethargic and be less likely to exercise.
- Diabetes- Sleep deprivation reduces insulin and therefore predisposes you to type 2 diabetes.
- Cardiovascular Disease- Sleep deprivation activates the sympathetic nervous system leading to an increased heart rate, increased vasoconstriction, blood pressure, cortisol and cholesterol. Interestingly a study on siestas in Greece showed that people who abandoned their siestas due to political and social pressure showed a 37% increase in morbidity from heart disease.
- Cancer- The increased inflammation throughout the body is thought to lead to an increased risk of cancer.
- Memory loss – Reduced sleep will lead to a reduced memory and cognitive function. A recent study showed a 20% improvement in memory with good sleep.
- An increased risk of musculoskeletal injury. With increased inflammation in the body, reduced time for recovery and rest there will be a correlating increase in the chance of injury. This is well documented below.
Prof. M Walker Effect of Sleep Loss. Why We Need Sleep. (2017)
In order to fulfill our duty of care and ensure force protection, and force generation for down graded personnel, we must educate our troops in the need for sleep.
Not just a marginal gain… a game changer
Sleep is the equivalent of a performance enhancing wonder drug. Not only does it reduce major health conditions, but it also optimizes performance.
Have you noticed that we often remember things first thing in the morning or wake up in the middle of the night with a random thought? This is because sleep allows us to consolidate our memories of the day. When we dream we compartmentalise our stressful events. Ever had a nightmare after a scary movie? It is whilst dreaming that we can relive events with reduced anxiety. This has big implications in the treatment of PTSD and other mental health conditions.
Sleep can improve a wide variety of cognitive functions such as attention, language, reasoning, decision making, learning and memory. If the overall aim of training is to ensure that service personnel have the technical skills needed to perform the job efficiently and effectively, we need to consider sleep as essential to learning.
Lack of sleep seriously affects our ability to concentrate on a task. This has big implications for driving. The Armed Forces tend to hold their mess functions on a Thursday night which normally ensures a fair amount sleep deprivation. The same applies to training exercises which finish on a Friday.
Both mess functions and training exercises that cause sleep deprivation before a weekend commute and drive home have serious implications for road users. When we are sleep deprived we micro-nap, causing a loss of consciousness which results in momentary complete loss of reaction.
If you combine driving with minimal sleep… ie. after a night out, we are a 2 ton accident waiting to happen. A cultural shift in the organisation of mess functions and the end of exercises is required in order to provide that duty of care to our troops.
Why do I sleep so badly?
In the natural environment the temperature rises and falls and our ancestors would have generally slept in a cooler night time environment. In our bedrooms we tend to have a room too hot, sleeping in pyjamas and with a thick a duvet.
The ideal temperature to sleep at is thought to be 18’c which tends to be far lower than our normal room temperature. If you want to sleep better, open the window, go Commando- get naked and turn down the temperature!
Whilst exercise though the day will help you sleep, we should avoid exercising too close to bed time. This will increase your blood pressure, heart rate and temperature and therefore make it harder to nod off.
Alcohol seriously disrupts our sleep. It suppresses REM sleep- which is why you’ll always feel tired on a hangover. Whilst a drunk sleeper will appear to be sleeping well, they are more likely to be in a slumber than actually getting good quality sleep.
Many people love a power nap. They are great for you, just not after 1500, as they reduce the sleep hormone adenosine and therefore make it harder to get to sleep later when you want to nod off quickly and get your full 8 hours.
The Alarm clock can seriously affect our sleep. Those clocks which give off a bright clock face will ironically keep you awake with the blue electronic light of the time. The alarm clock wake up will also abruptly pull you out of your sleep. Rather than setting an alarm on your phone try a ‘light up’ alarm clock. This brilliant piece of equipment utilises your circadian rhythm to ease you out of slumber by gently lighting up the room, similar to a sun rise.
Technology has a lot to answer for in terms of why we sleep badly. Mobile phones, IPads, Lap tops and televisions emits blue light. Blue electric light delays our circadian rhythms by up to 2-3 hours each evening by suppressing the melatonin release. Therefore our brain believes it should be more active, when it should be winding down.
Over the last 50 years we have seen a rapid increase in the use of technology which gives off blue electric light. In this period we have also seen a rapid decrease in the amount of average sleep people have each night. Interestingly we are seeing a corresponding increase in mental health disorders, obesity, cancer and a number of other major health conditions. It doesn’t take Einstein to see the link, or did it…
Albert Einstein reportedly had 10 hours of sleep per 24 hour period with regular naps throughout the day.
Winston Churchill enjoyed a good night sleep with regular non negotiable naps in the afternoon after lunch. He was thought to feel that his naps allowed him to get twice as much done each day.
James LeBron, the worlds greatest basketball player also gets around 8-9 hours sleep per night.
Throughout history, the greatest performers, thinkers and creative minds have thrived on sleep.
Is it time for a rethink?
We currently use sleep deprivation as a frequent training aide in the military with the aim of replicating the conditions of war; ‘train as you fight’. However, research has proven that you cannot train for, or become conditioned to sleep deprivation. Whilst you can develop some short-term coping strategies, there is no overall benefit of experiencing this regular exposure to sleep loss. Instead, it results in poor performance, lack of concentration and increased health risks. Therefore it is counterproductive to the overall aim of military training.
Nothing replaces the need for sleep.
As commanders, leaders and soldiers we need to rethink our approach and redefine the culture of sleep. It must be considered crucial to our recovery and vital to performance rather than being being seen as the trait of a lazy person. Troops should listen to their body and take sleep where needed rather than feel guilty when doing so.
For the reasons previously discussed, this approach should cover all facets of military life. Mess functions and ‘End Ex’ should be coordinated to ensure that it does not result in large numbers of personnel feeling forced to drive home to their families whilst potentially being sleep deprived.
In order to optimise the performance of our Armed Forces, we must ensure that our troops get more sleep than they currently get now. We expect and need a fit and professional soldier, sailor, airman and marine. We want our troops to perform like athletes, so it is time to improve our approach to sleep and start thinking about our troops with an Athletic Soldier mindset.
 M Walker. Effect of Sleep Loss. Why We Need Sleep. (2017)
 Naska A, Oikonomou E, Trichopoulou A, Psaltopoulou T, Trichopoulos D. Siesta in Healthy Adults and Coronary Mortality in the General Population. Arch Intern Med. 2007;167(3):296–301. doi:10.1001/archinte.167.3.296
 Chen, Y., Tan, F., Wei, L., Li, X., Lyu, Z., Feng, X., … Li, N. (2018). Sleep duration and the risk of cancer: a systematic review and meta-analysis including dose-response relationship. BMC cancer, 18(1), 1149. doi:10.1186/s12885-018-5025-y
 Potkin, K. T., & Bunney, W. E., Jr (2012). Sleep improves memory: the effect of sleep on long term memory in early adolescence. PloS one, 7(8), e42191. doi:10.1371/journal.pone.0042191
 Milewski, Matthew D. MD (2014) Chronic Lack of Sleep is Associated With Increased Sports Injuries in Adolescent Athletes Journal of Pediatric Orthopaedics: March 2014 – Volume 34 – Issue 2 – p 129–133
 Diekelmann S. (2014). Sleep for cognitive enhancement. Frontiers in systems neuroscience, 8, 46. doi:10.3389/fnsys.2014.00046
 Roehrs, T. and Roth, T., (2001) Sleep, sleepiness, and alcohol use. Alcohol research and Health, 25(2), pp.101-109.
 Anderson, K. N., & Bradley, A. J. (2013). Sleep disturbance in mental health problems and neurodegenerative disease. Nature and science of sleep, 5, 61–75. doi:10.2147/NSS.S34842