I used to meditate a lot.... And by meditate, I mean sitting with eyes half closed, and observing my thoughts or breath.
I found this to be energizing... I could get by on less sleep (5-6 hours vs 7-8).
For every ~ hour I meditated, it was ~an hour less of sleep that I needed.
Not sure what is happening to the neurons during meditation. I do recall a talk with HH Dali lama and physicists on you tube that may provide some insight. ✨🙏