What is sleep and why is it needed? In medical textbooks, sleep is generally defined as “a reversible behavioral state of perceptual disengagement from, and unresponsiveness to, the environment.” A state entered into by all animals, all the way down to lizards (and perhaps beyond). But why? Although much has been associated with the consequences of sleep (good and bad) the jury is still out on the biological nature of its requirement. But its evolutionary persistence – coupled with even the lethality of extreme deprivation – help to underscore its importance.
Beyond the consequence on cognition, sleep deprivation (even a single night) is known to have acute effects on the endocrine system. Particularly prominent is the spike in the level of ghrelin, the so called “hunger hormone,” which drives those sleep deprived to the vending machine, and then eventually to consequences thereof. Perhaps next to exercise nothing has been associated with as many medical benefits as sleep.
But can we get by and still be exceptional with less? History suggests – although little hard evidence exists – that Leonardo Di Vinci, Napoleon, Nikola Tesla were among some of the influential people of their times who benefited from what has since been termed polyphasic sleep – a work schedule designed to secure more hours of wakefulness per day. Even today sleep, or the suggested ability to need less, is offered as evidence (or even as bragging) of an individual’s commitment or suggested productivity. It is certainly clear that we “can” survive on less and for some, perhaps even more so, but with less sleep how profoundly and specifically does our productivity decline? The answer for all of us is quickly.
Many institutions and organizations like hospitals, the military and NASA have studied sleep in great detail in an effort to understand how best to support personnel in situations in which sufficient sleep is simply impossible. Collectively, these studies show that individual variation in optimal sleep quotas per day exist, and that some accommodation to sleep deprivation can occur. But the most substantial change is in our perception of our performance. When operating on less than optimal amounts of sleep we “believe” we are performing much better than we actually are, while we also tend to opt toward activities with reduced cognitive complexity.
Athletes (particularly those on traveling teams) have complicated adjustments to make regarding sleep. One particularly interesting study was conducted at Stanford involving the men’s basketball team. To begin, the team members were asked to wear wrist accelerometers nightly to log their sleep schedules – which came in at ~6.5 hours per night. For the first two weeks, the team kept to their normal schedules and they were precisely tracked on measures of performances in sprint drills, free throws, and three-point shooting. For the next 5-7 weeks the team agreed to seek as much sleep as possible, with a goal of 10 hours of sleep per night. Although that idealized target was not hit they did achieve a 24% increase in sleep per day (going from 6.5 to 8.5 hours). Then their performance was re-measured and the increases were striking. Approximately 9% percent increase in free throw and three-point shot percentages were achieved while every single member of the team was significantly faster in the 282-foot sprint drills (P < 0.001). Significant performance increases that would typically have taken years of additional practice were accomplished within just over a month of getting two hours of extra sleep per night! While this study doesn’t prove that sleep was, by itself, the sole performance enhancing elixir, it certainly suggests getting more sleep can quickly help.
How these athletes got so much better that quickly remains a mystery, but recent brain imaging studies may provide additional clues. One of the key differences between our brain and other organs relates to the architecture of its circulatory system. Given the centrality of the brain to our survival, it is further protected by a membranous sheathing system often call the blood-brain-barrier or “BBB.” Within the BBB, both active and passive transport systems are present to ensure that sufficient fluid and nutrients are always present, while at the same time the BBB stringently resists access to toxins or pathogens that might be present in the blood stream. Until recently it was believed that these exchange processes operated at steady-state, day and night. But what has been learned recently is that during sleep the export of materials from the brain is dramatically increased. By mechanisms that are still poorly understood, the physical features of the BBB change during sleep (perhaps even changing the volume of the brain itself!) encouraging the efflux of brain accumulated waste products back into the blood stream for renal and/or hepatic clearance.
Is this it – the explanation for why we just cannot seem to get by without slumber? That for effective function, the brain requires a daily rinse cycle! This notion is particularly interesting to consider in the context of the association between sleep deprivation and mental conditions like Alzheimer’s, where the inappropriate accumulation of beta-amyloid in the brain is thought to be pathogenic.
The start-up world has a long history and culture that “demands” 24/7 engagement with sleeplessness being the norm. But these trends are changing, with leading entrepreneurs and their investors beginning to rethink how to build winning teams from these “corporate” athletes. Sleep pods, and even sleep talk are making it into the dialogue and planning.
So where does this take us? For some, getting enough sleep is certainly not a personal choice considering as many as 10-30% of adults suffer from insomnia in a given year. Some derived from temporary stress – whereas in others – conditions such as sleep apnea or pain interfere with achieving deeper sleep stages. For others, we seem to have slipped into troubling habits driven by our jobs, or with electronic devices, late-day consumption of caffeine, alcohol or other poor “sleep hygiene” rituals.
What we can all do is to begin to care – to keep track of the amount and quality of sleep that we are getting (here is where those e-devices can truly help). To use these details to decouple the bad habits that are truly keeping us back. As companies and leaders we can personally emphasize the importance that we place on the sleep-enabled well-being of our colleagues and co-workers. Aetna is a particularly impressive example, with its $500 for 20 consecutive 7 hour sleep days health and wellness program.
In a few weeks, many places across world will shift their clocks one hour in the “fall back” reset from daylight savings time to standard time. This provides the perfect opportunity for the personal experiment – the opportunity to actually take notice of what just one night of one extra hour of sleep can actually feel like. We can see (and feel) for ourselves the #powerofanhour and how one amazing thing…can lead to another.