NASA’s nap program – sounds like a joke? It’s actually reality.
NASA did experiments to have their astronauts take short (max 20 min) naps alongside their 8-hour sleep routines. Results (increase in alertness, lower margin of error) were so surprising they actually expanded the program to all terrestrial workers as well.
The science of naps fuels a lively discussion on how humans are meant to sleep. Feeling drowsy after lunch? You think it has to do with that extra sandwich you had? Think again. If one would take a brain scan of most people at around 13h00/14h00 in the afternoon, you would see a rise in adenosine (the hormone responsible for ‘sleep pressure’ – hence making you feel sleepy) – regardless whether you ate 7 hamburgers or nothing at all.
This might indicate that humans are not made to sleep in one phase (as most of us do – 8 hours at night) or ‘monophasic’ sleep but in a 'biphasic' schedule: one long phase and one shorter phase.
So, what does it mean for you? Do you need to nap? Not necessarily. If you struggle to fall asleep at night, it is recommended to NOT include naps, so you can take full advantage at night of the built-up sleep pressure (adenosine levels). If you do choose to nap, keep it short (20 minutes max) so you don’t go into a deeper phase of sleep – leaving you drowsier when waking up. Avoid naps after 14h00 in the afternoon and definitely avoid ‘accidental naps’ right before bed (so if you feel yourself falling asleep in the couch => surrender and go to bed instead, otherwise you might find yourself staring at the ceiling later at night).