In times of stress, often the first thing to go from our priority list is getting a good night’s rest. We often work late into the night, or spend a little too much time unwinding from work, finding that we have to be up in less than 6 hours. Does missing your normal sleep time matter that much? And how much effect does this have on your mood, appetite, productivity and even health? The truth is, sleep is almost as vital as our normal basic functioning like breathing, drinking and eating, yet is often the first thing to be neglected. Not only do we recover from mental and physical stress during sleep, we also enhance our memory, learn and grow.
Missing an hour or two here or there doesn’t make much of a difference, does it? In fact, the average duration of sleep needed for health and wellbeing for an adult is around 7-9 hours, depending on your physiology, life stressors and circumstances. We cast our minds back to our younger years where one could be fully functioning on 5 or 6 hours a night, yet this deprivation is much more noticeable in our later years, despite older individuals getting on average way less than the recommended amounts.
In fact, many health conditions have early symptoms of sleep deprivation and insomnia, a sign from our body and circadian rhythms (the internal body clock) to tell us what’s wrong. Indeed, a cycle exists whereby bad health can cause poor sleep, yet poor sleep further feeds into the feedback mechanism by exacerbating ill health. In recent years, sleep deprivation has been well established as a main factor in the prominence of mental health conditions and as a co-morbidity in some of the major causes of death worldwide; heart disease, cardiovascular disease, cancer and diabetes.
When we neglect our rest for a long enough period, our emotional resilience, mental toughness and ability to concentrate are massively undercut, leading to nervousness, anxiety and eventually depressive episodes. Not only do we have trouble with cognitive tasks, but sleep deprivation can make emotional regulation challenging – making everything seem worse than it is. Counterintuitively, though, it is not the duration of sleep that is most important, rather the quality of the sleep we get, which are reflected through the stages of sleep and rapid eye movement (REM). Sleep is broken into stages: Non REM, 1,2,3 and REM sleep.
Stage 1 sleep is rather like drifting. In this period, the brain activity slows and our muscles relax – a sort of ‘preparatory phase’ for later, more important parts of sleep. This near wakeful stage is where most individuals stay and return to over the course of the night, before transitioning to stage 2. Stage 2 sleep is where memory, learning and processing occur, yet still in a relatively light stage compared to stages like REM. In this stage, only certain neurons are activated in the brain to increase the efficiency of transfer from one stage to another, and to allow for complex processes in the ‘refreshing’ of the brain.
Stage 3 of sleep is the first stage of deep sleep, where most humans probably spend an hour to an hour and a half in each night. Here, brain activity slows significantly and muscles lose a lot of their resting tones to support maximum relaxation. In this stage, immune functioning is heightened alongside releases of growth hormone and other restorative hormones which focus on tissue repair, bone growth and muscle recovery. After this stage, the brain enters deep REM sleep, the stage where dreaming occurs and there are sporadic bursts of brain activity, muscle movement and an increase in blood pressure and heart rate. After 90 minutes in bed, this stage is reached, and may cycle as many as 8 times in a night, each time lasting around an hour each. On top of that, a lot of processing and memory occurs in this stage where experiences, information and memories are transferred into long term memory.
Poor sleep quality and environments not conducive to good sleep hygiene don’t readily permit the introduction of the brain to the latter, more restful stages of sleep. Thus, on a rebound from a long night out, we may feel more fatigued, less emotionally resilient and even have trouble concentrating. Waking up in the middle of a deep stage of sleep can disrupt the brain significantly, leaving the ‘foggy’ feeling of fatigue and malaise which can be carried around all day. After much research, it has been demonstrated convincingly that poor sleep quality are risk factors for things like cardiovascular disease and cancer. In fact, a near 20% risk in certain cancers can be demonstrated with chronic sleep deprivation.
Likewise, oversleeping can also increase the risk for sedentary-associated conditions like colorectal cancer and diabetes. However, the links to these disease is as of yet tentative – but reducing any of the other comorbidities which, in conjunction, can predispose these conditions is a positive step. Practicing good sleep hygiene like setting common times for sleep each night, reducing snacking in the evening, switching off mobiles and devices can really help in getting a better start to your nights rest. With almost 1/3rd of the population experiencing regular insomnia, the battle of getting to sleep is one that can be isolating and lonely, but can be partially managed by improving lifestyle factors and giving yourself the best chance at relaxation.