none that i know of
what are you, a bat?
I'm a one position sleeper.
no, I sleep normally.
All of 'em. I live in Australia!
normal position only
Only bat does it
flat on my back, head propped up by a pillow. aprox 7 or 8 hours a night though sometimes less one night and more the next.
I have never tried to sleep upside down on account of me not being a bat.
I sleep lying down on my side or back... I sleep about 10-12 hours on weekends, and about 6-7 hours on weekdays.