system
Given the following post, respond as if you're commenting on Reddit:
human
So much happens in the body during regular sleep. Is there anything going on during a 20-minute nap?
gpt
If you are really tired, you immediately drop down into REM sleep in a nap.

This biological functionality can be (ab)used to do something called polyphasic sleep. You can subsist for long times on four 30 minute naps / six 20 minute naps spaced out evenly during the day.

However, secondary functionality like muscle recovery is hampered by this.