On a related note, I wear a fitbit and if I sleep from say 12-8, you'd think this would be 8 hours of sleep (as recommended) but I usually have about 1 hour awake or restless (according to the fitbit). So fitbit says I got 7 hours of sleep.
The question is do these studies account for this supposed awakeness that seems to be part of everyone's night of sleep? Surely nobody that reads them thinks they need 8+1 hours when the study says 8 hours is good...
I think most recommendations are to get 4-5 sleep cycles a night, so the actual elapsed time will vary for individuals.
The problem with chronic sleep deprivation is that you miss one or more cycles, It's like if you washed your clothes but skipped the rinse and/or spin cycles. Skipping a whole night of sleep and you're still wearing yesterday's clothes.
The question is do these studies account for this supposed awakeness that seems to be part of everyone's night of sleep? Surely nobody that reads them thinks they need 8+1 hours when the study says 8 hours is good...