We all know the power of a good night sleep. It allow your hormones to function properly, you consolidate your memories from the day, your body goes through its natural repair processes, your brain gets a nice wash removing all the toxic proteins, you restore your energy levels, etc, etc. But what about napping? Does this mini sleep actually do anything for us? We all feel better after a nap (if your even able to unplug long enough to nap), but what else is going on during our siesta?
A nap, typically defined as 15 to 90 mins of daytime sleep according to sleep.org and Dr. Sara Mednick, author of TAKE A NAP:CHANGE YOUR LIFE, can be incredibly beneficial for a cognitive as well as physical boost during your day.
During our naps, we are dropping into our sleep cycles we experience at night. According to sleep.org these are:
Stage 1- This is our "catnap" stage. Usually lasting only a few minutes, our bodies are slowing down and preparing us for deeper levels of sleep. Our eyes start slowing down, our brain produces more alpha and theta brain waves, and we can be easily woken during this stage. (Pretty sure I've had this during some of my math classes growing up- with my eyes open).
Stage 2- Now we've dropped from 1 to 2, our brain waves begin slowing as well. Similar to 1, we can be woken somewhat easily from this stage.
Stage 3/4- Beginning of deep sleep and delta waves release, we do not wake up as easily because our bodies become less responsive to outside stimuli. This is when the "body repairs muscles and tissues, stimulates growth and development, boosts immune function, and builds up energy for the next day."
REM- This stage usually occurs 90 minutes after falling asleep. During this final phase of sleep, our brains becomes more active, and this is when most dreaming occurs. Your eyes begin moving quickly, heart rate and blood pressure increase, and breathing becomes "fast, irregular, and shallow." REM is hugely important in memory and learning, since this is when the body consolidates the days events into your long term memory.
So which stages are we in during our naps? According to most professionals, you typically want to either get a quick power nap (20-30 min) in or go big (90 min). If we look at the stages above, we see that means we'll probably just be finishing up stage 2 sleep or just entering REM.
While there are no hard rules saying you can't wake up in the middle of stage 3/4, you'll probably wake up feeling pretty groggy from this. If you think about it, this is when your body is concerned more with the hardware (the body itself) rather then the software (brain and nerves). If in the middle of all the body work- waking up pulls you rapidly in a completely different direction from seconds before.
Besides time being a factor- usually the quicker stage 2 naps will effect the periphery more. This means that you'll improve your motor skills and attention. REM sleep will more likely effect your central nervous system, possibly creating new neural connections in your brain.
A cautionary tale- recent studies (https://www.researchgate.net/profile/Judith_Hays/publication/14558726_Risk_of_Napping_Excessive_Daytime_Sleepiness_and_Mortality_in_an_Older_Community_Population/links/00b4953a0fc12658c9000000.pdf,
have indicated the correlation between naps and mortaility. The researchers point out it may be a chicken or the egg conversation, being that excessive daytime naps be a sign of underlying health issues (sleep apnea, insomnia, stress, etc) or a sign of not enough night sleep.
Make sure you are sleeping for the right reasons- a quick pick me up instead of reaching for another cup of coffee or energy drink. If you find yourself constantly needing a nap and not waking up refreshed- it may be time to go visit your Dr!