system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do I feel less tired in the morning after only sleeping a few hours rather than sleeping a full night (8 hours)?
gpt
Sleep cycles are approximately 1.5 hours. So you're better off with 6, 7.5, or 9 hours sleep. 8 hours is a bad amount of time to sleep. The further into the middle of a cycle you are, the more you feel like crap when you wake.