We all ‘know’ that sleep is important, and being reminded each time we don’t prioritise sleep duration and quality, and have to suffer the consequences of lack of energy, concentration, memory, illness, mood swings….etc. But what actually happens during sleep, and how much do humans really need to function optimally?
THE ELITE clients are lucky enough to receive a full education module on Sleep- As it is NOT a pillar of health along with exercise and nutrition (Figure 1), it IS the foundation of health, in which the other pillars of health completely rely on (Figure 2). Because of this, we ensure sleep is prioritised for maximal performance and function.
The stages of sleep
So what actually happens during sleep that resets our minds and bodies so comprehensively each night? Sleep contains 5 unique stages – Stages 1-4 are called NREM (Non-Rapid eye movement) and the 5th stage is REM (Rapid Eye Movement), commonly known as the dreaming stage of sleep. Within a full night’s sleep, a person will go through 4-6 cycles of stages 1-5, with one cycle approximately 90 minutes long.
Although a person is completely unconscious to the external world during sleep, the brain is working very hard during sleep to refuel, replenish and recover the brain and body for the next day. Each of the NREM and REM stages have their own programmed purpose, as seen in table 1 below.
Table 1: A cycle of sleep and its function.
Although humans cycle through each of the stages of sleep throughout the night, NREM is more dominant in the first half of the night, and REM in the second half. This is where people can really deprive themselves of either NREM or REM sleep, losing NREM through the delay of bedtime being on technology, or the use of early alarm clocks and prematurely jolting themselves out of the deep REM sleep. Unfortunately, once depriving oneself of the daily NREM or REM sleep, the benefits of refining that day’s neural activity cannot be caught up on. Even three night’s of recovery sleep does not equal regular eight hours nightly, and given that most people only get two-day weekends majority of the year, there is a serious epidemic of chronic sleep deprivation.
If this doesn’t alert alarm bells enough for one to get a full night’s sleep EACH night, studies have shown that humans consistently underestimate the degree of performance disability from lack of sleep. Consequently, a suboptimal level of performance, alertness and energy becomes the baseline for society.
How much do humans really need?
So how much sleep do humans really need? There have been plenty of studies on this topic, and time and time again, the results are unanimous. The sleep that humans obtain ‘naturally’ (Without the use of an alarm clock), is NOT necessarily what is needed for optimal function and health, this is especially obvious in those with insomnia, the elderly who struggle to sleep but suffer subsequent illness etc.
The human recycle rate is 16 hours of wake time, and 8 hours of sleep time every day. This ratio has been shown for optimal concentration, memory, alertness, logical thinking, problem solving, injury risk, physical performance, illness, mood, and the list goes on. David Dinges from the University of Pennsylvania has shown in his research that 6 hours sleep a night for 10 consecutive nights leads to over 400% more frequent lapses in concentration, which equivalent to going a full night without sleep. It only took 6 consecutive nights of 4 hours a sleep for the same detrimental effect on concentration levels. Those with 8 hours sleep had near performance over the two weeks of the study. This is only one study on concentration levels, and there are many others linking sleep deprivation to almost every human illness, disease and injury.
Sleep is not JUST a pillar of health, it’s the foundation of health in which your physical training and nutrition sits on. If you want optimal performance in the workplace and out on the sporting field, be sure you allow yourself the opportunity for at least 8 hours in bed each night. Forget about those boasting about functioning on 4 hours sleep, they’ll no doubt be suffering the consequences sooner or later. The next article will be an in-depth overview of the 8 main consequences of sleep deprivation. Be sure to let all your night-owl friends know about it!