[tartoran]

Personally, I am very alert throughout the day if I sleep between 6-7 hours. Past the 7 hours threshold I am get into a worse headspace (brainfog) throughout the day proportionally to the amount of extera sleep.

[ycombinete]

Sleeping for longer than 8 hours frequently gives me hypnic headaches and terrible migraines.

I recently had a baby and the lack of sleep has reduced my headache frequency dramatically!