Let’s face it. Whether the reason is a long day, a poor nights sleep or something completely different, people get tired throughout the day and being tired can really drag down your performance. It’s only natural to want to put what you’re doing down and fall back to sleep for hours and hours. The problem more often than not is that that initial feeling of wanting to let go for a little bit often can take you far past feeling rested into a re-vamped state of tiredness and grogginess. So here’s the question: what is the right balance of sleep to make you feel rested and not groggy?
What Exactly is Sleep?
The science of sleep is an interesting one. Sleep, fundamentally speaking, is the period in which your brain releases consciousness and reduces sensory activity putting you in a “semi” unconscious state where anabolic activity including growth and rejuvenation of the brain and body physically take place. Sleep and general rest is essential in all forms of life to maintain proper organic functions and behaviors. Lack of rest is well documented and can lead to things seemingly unrelated to sleep including heart disease and weight gain.
Understanding the Cycles of Sleep
Sleep functions in 5 cycles or layers across a continuum. One layer leads into the next through a transition. There are 5 main phases of the sleep cycle:
The first two phases are referred to as the Light Sleep phases, the third stage is the Deep Sleep phase and the fourth and fifth stages are known as the Rapid Eye Movement phases (REM for short). Rapid eye movement coming from one hypothesis that believes the eyes are moving in alignment with dream activity. In other words, if you’re dreaming yourself running and jumping, your eyes during REM would match the movements of running and jumping.
During the light sleep phases, stages one and two, the body transitions from a period of wakefulness to sleep. Typically, these first two stages span 10-30 minutes when the brain is at the brink of falling asleep (if you’ve ever caught someone “resting their eyes” – you’ve seen stage one sleep in action) and a gentle phase of sleep where the brain is entering a more subdued state, but not one that would induce the wicked grogginess if awoken. Beyond the third cycle the body begins to fall out of consciousness and into a more rested state where brain activities begin to change and slow down and dreams can begin to occur.
What Makes a Perfect Nap?
Typically between 10-30 minutes is the optimal time for a power nap. More than 30 minutes than your body will experience sleep inertia, that feeling of having “slept too much” and the desire to return to bed i.e. grogginess. Fewer than that gap of time and your brain has not yet had the time to engage in memory consolidation, the phase when the brain begins to condense information and knowledge learned throughout the day. The consolidation leads to improved memory functions, cognitive activity, increased creativity and, of course, restfulness.
Some cultures even have the concept of the power nap imbued into their way of life, demonstrating just what kind of wonders it can work. In Spanish culture, after the large midday mean, comida, the custom is to take a “siesta del Hidalgo” (or “the Gentleman’s nap” for short – or simply “siesta” for even shorter.
So the next time you’re feeling tired around 2pm, go ahead and make some time for sleep. And if you’re at work when this happens, make a case to your boss that sleep on the job will actually increase and improve productivity.
Check out this cool 2 minute video on sleep and power napping!