The  IYO summary

Ideally an adult need 7 – 9 hr per night.  One out of two tries to survive on  6 or less hours during the week.

Not so long ago, surviving on 4 – 5 hrs of sleep was viewed as an admiriable trait, pulling an all nighter considered a badge of honor. In the last decade that idea has been completed shattered. Adaquate sleep is now considered critical for physicial and mental health.

If you are not getting enough sleep, here are some simple suggestions that may help.