I have the opposite problem as the first post. If I sleep too long, my body lets me know and I get up.the only time I sleep more than 8 hours is if I'm sick or worn out from doing way too much. I get an average of 4 to 7 hours of sleep a night, denpending on the weather, what I did that day, how I feel, etc. Like others have said, the more you do and the more you exercise, the better you sleep and the less you require.