We all know sleep is important, but how much sleep can we lose before short or even long-term effects begin to culminate and negatively affect our bodies? How does this affect our ability to make sound decisions?
Sleep is a basic biological necessity that, much like water and food, our bodies cannot live without.
What are the different stages of sleep?
Stage 1 (non-REM): (1-5 minutes) Initial stages of sleep where your body begins to transition between its conscious awake state to sleep, eyes still move rapidly relative to light sensitivity.
Stage 2 (non-REM): (10-60 minutes) Your body temperature lowers, breathing and heartbeat slow. Although there are still bursts of electrical activity, the majority of the body’s average sleep cycle is spent in Stage 2. Your body begins to prepare to enter a deeper state of sleep.
Stage 3 (non-REM): (20-40 minutes) This stage is depicted by the lowest level of heart and breathing rate. Brain activity is slowed and so the body enters a deep state of sleep. During this state of non-REM sleep your body begins to repair itself regrowing tissue and repairing muscles. At this stage the body replenishes its energy stores and allows for cell regeneration.
REM Sleep: (10-60 minutes) Occurring after approximately 90 minutes of sleep. Infants spend about 50% of their time in the stage of sleep as opposed to adults spending only 20% in this stage. REM sleep research also suggests that during this stage of sleep consciousness, the brain functions to consolidate labile memory.
During this stage the brain's efforts are focused towards removing toxins and cellular by-products such as soluble proteins and metabolites from the central nervous system accumulated throughout the day. The brain, in all its complex capabilities, works either cleaning and replenishing these glymphatic systems (while sleeping) or process sensory information (when awake). As you can imagine, the disruption of this process consequently results in a build-up of neural waste. In addition to this, the body is also not able to effectively replenish muscle and energy stores.
From this we can see that stage 3 non-REM and REM sleep would be seen as the optimal zone our bodies function to provide physical and cognitive recovery.
Adults between the ages of 18 and 25 years old should seek to achieve 7-9 hours of (unbroken) sleep daily to be in order to replenish the body’s metabolic stores. Personnel who regularly sleep less this are in a state of sleep deficiency whereby their body is consistently working to “make-up” for lost recovery time.
Effects of sleep deprivation
Short term effects of mismanaged sleep may present themselves in the form of slowed cognitive and motor functions, mood irregularities, micro-sleeps and impaired judgement; the severity of these effects correspondingly increasing with the consistency of being in a state of sleep deprivation.
Progressed stages of sleep deprivation can closely resemble symptoms of acute schizophrenia – resulting in the inability to differentiate between imagination and reality, irritability, elevated levels of anxiousness, hallucinations, visual distortion, and even depersonalisation.
The ensuing consequences of sleep deprivation on cognitive and physical functions should be heavily avoided where possible.
How does this affect me?
The conventional and non-conventional operating environments that the modern-day battlespace is now evolving into affords personnel limited time for rest. Moreover, the parameters surrounding this progressive battlespace (especially cyber) also require personnel to operate closer to sensory threshold than ever before.
Sleep is regularly overlooked as an imperative part of performance. There is also a culminating risk when prolonged sleep deprivation continues to degrade the effectiveness of personnel. Increasing and maintaining productivity therefore relies heavily on managing the rest of subordinates.
Likewise, in understanding subordinates’ limitations, the same considerations should be applied to your ongoing self-assessment of your ability to accomplish your role as a leader. Ensuring you can make effective decisions to lead requires you to maintain a consistent balance of work, as well as rest.
Moving forward
Sleep deprivation can be overlooked in training, which then translates further into wider Defence. Due to the battlespace that soldiers and officers inherently operate in, risk awareness and management training is essential. However, there still remains a gap in rest management within Defence.
During my time as a regular service solider (prior to commissioning), training based around sleep and rest were undertaken only with relevancy to subjects that were promotional or licencing based. Emphasis was put into anything that would result in legislative action as opposed to a proactive response to things like increasing productivity.
To combat this, informative training packages can be produced to promote the view of sleep as a primary necessity with the same importance placed on food, water, and weapon handling. Training would look to include details of different stages of sleep with particular emphasis on the benefits of sleep recovery, sleep hygiene, and work productivity in relation to long-term and short-term effects of sleep degradation. Similar to a Strength Deployment Inventory test taken for promotional courses, awareness of sleep deprivation can be integrated into conflict response and conflict resolution training.
This type of training would be better structured around a point of reference whereby trainees experience an arduous exercise specifically tailored to exploit their lack of sleep. As prior training to these exercises, trainees would be first educated on the matter before first-hand experience. Following the exercise, a rehash of the subject and personal reflection of their experience can then be used to further assimilate their awareness that equipment husbandry extends beyond weapons to our bodies as well.
Conclusion
A greater importance of the management and effects of sleep deprivation needs to be actively discussed as a basis of personnel welfare. The biggest asset of any military is its personnel. By filling the gaps in our own understanding of the multiple facets of personnel welfare, we can remain readily effective as a deployable defence force.
Further reading:
Eugene, AR 2015, “The Neuroprotective Aspects of Sleep” viewed 15 February 2022, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651462/.
DiGiulio, S 2017, “What happens in your body and brain when you sleep?” viewed 20 February 2022, https://www.nbcnews.com/better/health/what-happens-your-body-brain-while-you-sleep-ncna805276.
Killgore W.D.S 2010 “Effects of sleep deprivation on cognition” viewed 20 February 2022, https://www.sciencedirect.com/science/article/abs/pii/B9780444537027000075.
Murphy, PJ 1997, “Sleep Onset”, Publisher American Sleep Disorders Association and Sleep Research Society, viewed 20 February 2022, https://academic.oup.com/sleep/article/20/7/505/2732131?login=true.
Natural patterns of sleep, Division of Sleep a Harvard Medical School, viewed 22 February 2022, http://healthysleep.med.harvard.edu/healthy/science/what/sleep-patterns-rem-nrem.
New Zealand Defence Force, viewed 22 February 2022, https://www.nzdf.mil.nz/nzdf/where-we-are/waiouru/.
Nunez K & Laxoreux K, “What is the purpose of sleep?” viewed 20 February 2022, https://www.healthline.com/health/why-do-we-sleep.
Pilcher J.J & Huffcutt A.I, “Effects of sleep deprivation on Performance: A Meta-Analysis” Publisher American Sleep Disorders Association and Sleep Research Society, viewed 12 February 2022, https://academic.oup.com/sleep/article/19/4/318/2749842?login=false.
Schlundt, M 2021 “A sleep cycles overview: A deep dive into each stage of sleep” viewed 22 February 2022, https://www.sleepcycle.com/sleep-science/sleep-cycle-stages-deep-dive/.
Schonauer, M & Pohlchen, D 2018 “Sleep spindles” viewed 22 February 2022, https://doi.org/10.1016/j.cub.2018.07.035.
Suni, E 2020 “What happens when you sleep” viewed 22 February 2022, https://www.sleepfoundation.org/how-sleep-works/what-happens-when-you-sleep.
Taheri, M 2013, “The Effect of Sleep Deprivation on Choice Reaction Time and Anaerobic Power of College Student Athletes” viewed 20 February 2022, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3307962/.
