How can you easily improve your memory, creativity, and focus to be at your mental-best each working day? How can you increase your energy so you have more of a willingness to follow an exercise routine? How can you very quickly improve your blood pressure and heart health, and also improve your ability to lose body fat? You can do all of this with the most influential performance enhancer of them all: a good night sleep.

The World Health Organisation recommends getting 8 hours of sleep each night for optimum health. Sadly, two-thirds of adults throughout all developed nations fail to obtain this amount of nightly sleep.

A Japanese study that spanned 14 years, monitored the health effects of 4,000 male workers and compared their sleeping habits. The study concluded that those who were getting 6 hours of sleep or less were 400-500% more likely to suffer a heart attack when in contrast to those who were sleeping more than 6 hours each night. In other research, every year 1.5 billion people around the world adjust their clocks, as they switch to/from daylight savings time. As the days become longer and we go from spring to summer, we move our clocks forward 1 hour, losing an hour of sleep as a result. What global hospital reports show is that when we lose just this 1 hour of sleep, heart attacks increase by 24% the next day. On the flip-side, when the other half of the world move from autumn to winter, and they gain an extra hour of sleep, hospital reports show a 21% decrease in heart attacks the following day. It sounds unbelievable, but it’s true! How can losing just one hour of sleep each night contribute such a massive percentage jump? It makes you think how fragile your health can be if you’re one of the many who are constantly under-slept and sleep-deprived. The common joke is when people say ‘I don’t have time to sleep’ or “I’ll sleep when I’m dead’ is rather unfortunate, as if you adopt this mind-set you will be dead sooner and the quality of that (shorter) life will be worse (1). Sleeping less than six hours a night is directly correlated with not only death from all causes, but death from specific causes as well: cardiovascular disease, cancer, mental illness, diabetes, or accidental death from fatigue (often from a motor vehicle accident).

The reason why humans need to sleep for 8 hours each night, according to the latest sleep science, is to keep in tune with the human body’s natural circadian rhythm that we have evolved and developed for millions of years. The circadian rhythm is a naturally occurring daily clock that’s set within our brain, and it communicates daily human processes like when to be awake, when to sleep, when to eat, it affects your mood and bowel movements, and it helps to release hormones to keep your body finely balanced. Modern science and MRI scanners have helped us better understand and observe the neural activity that goes on in the human brain, and we can now compare the differences when we sleep versus when we don’t sleep enough. When our sleep patterns are in tune with our circadian rhythm, thus being 8 hours asleep versus 16 hours awake, we can optimally store and remember new memories, embed new motor skills (learned via a skill, sport or exercise), remove metabolic waste that builds in our brain (while we are awake), and prepare our body to be in an improved condition for the next day.

By getting a full 8 hours of sleep, the brain can cycle between two distinct phases, called NREM (non-rapid eye movement) and REM (rapid eye movement) sleep. Each of these sleep stages has different roles to play, and each of these are equally important to learning and retaining new knowledge. These two phases of sleep occur in 5 typical 90 minute cycles over an 8 hour period throughout the night. NREM sleep is more abundant at the beginning of the night when we just fall asleep. NREM sleep is often referred to as deep sleep, where the main purpose is to transport the most recent memories of the day from the hippocampus (the short-term memory centre) to the cortex (the long term storage area of the brain). NREM sleep in effect hits the ‘save button’ on any newly learned memories of the day, and by doing so, it clears the hippocampus so that we are ready to take in new memories the following day. REM sleep does occur all throughout the night as part of a cycle between the two different stages of sleep, however it is more abundant in the final 90 minute cycle of an 8 hour sleep period. REM sleep is a critical stage of the sleep process, as the brain takes those newly saved memories that was generated from the deeper NREM sleep stage, and collides those new memories with past memories, therefore building more refined and better new associations with what we’ve just learned – inspiring creativity. Getting sufficient REM sleep can often explain that “a ha, now I remember” moment, when suddenly the brain recollects a memory that was once forgotten. This is a key reason why short-sleeping, and not getting a full 8 hours of sleep can deprive the brain of this REM sleep stage that is critical in helping us better understand new ideas and concepts that we have experienced when we are awake.

From a physical point of view, it’s not a big surprise that getting a good night sleep prior to exercise will improve your energy and athletic performance the next day. Which means that your overall strength and fitness will improve faster because you’re able to put in better quality efforts when you are training. However, there is also much benefit to getting a full night sleep post exercise. Post-performance sleep accelerates muscle repair, reduces inflammation, improves central nervous system recovery, and improves memory (2)

See the performance stats below that shows National Basketball Association (NBA) player Andre Iguodala, of the Golden State Warriors. The image shows the improved performance of key game output when 8 hours or more of sleep are achieved, compared with having less than 8 hours of sleep (3)