sleeping hours for maximum growth

[fitguy]

usually when i sleep 6 hours or less i feel that i cant have a proper workout and i aint sure if thats psychological thing or cause 6 hours aint enough and was wondering whats the least number of hours that anyone should have for optimal muscle growth

[BJJ]

I am not aware if there are studies on this topic, in relation to aas I mean; surely there mus be.
For convention we have a day of 24 hours, so I would say 1/3 of that, so 8 hours at least.
I also do not feel very good if I sleep only 6 hours and in the early afternoon I need to take a nap otherwise I am a zombie for the remaining of the day.