Yet, for many of us, our sleep is defined by unpredictability. And at one time or another we have all experienced the immediate next day adverse consequences that accompany insufficient or poor-quality sleep. These can include fatigue, inability to think clearly, lack of motivation, having a ‘short fuse’, headaches, gastrointestinal discomfort, the list goes on. Indeed, thanks to the science of sleep, we now know that the function of virtually every organ in the body and in fact every cell in the body is impaired with inadequate or disrupted sleep. For example, if you stay awake for 19 hours in a row your performance and alertness decrease to levels equivalent to a blood alcohol concentration of 0.05%. If you extend to 24 hours awake, it increases to 0.1%, double the legal limit for driving. Alternatively, if you restrict sleep to just five hours for five nights in a row, performance and alertness corresponds to a blood alcohol concentration of 0.05%.
Beyond performance and alertness, if you measure blood glucose and testosterone levels before and after five nights of five hours sleep in an otherwise healthy young man, glucose control diminishes to a level comparable to a prediabetic state and testosterone levels fall as though he has aged a decade. These are just a few examples of why prioritising enough time to get sufficient good quality sleep on a regular basis is essential for optimal health and wellbeing.