According to the fitness tracker I wear on my wrist, I slept for 7 hours and 13 minutes last night.  I was restless eight times and woke up twice.  What does that tell me?  No idea.  The Centers for Disease Control tell us that adults need seven or more hours of sleep each night.  But what if I feel refreshed after five hours? Am I unhealthy?  What if I slept 10 hours, am I super healthy?