| This is a great question. As others said, the data is contaminated. Likely people who are sick sleep a lot more. That said, I'm one of those people (healthy, I think) who sleeps 9-14 hours every day. My goal every night is to sleep as long as I possibly can. Nights when I only hit 9 hours is usually because I had to get up to go the bathroom. I have Sleep Apnea but treat it with a CPAP and went from 20 awakenings per HOUR to just 0 to 2 per NIGHT. But the amount I need to sleep hasn't changed for some reason. I definitely feel dramatically more rested after sleep than I used to though. I started using AutoSleep app with Apple Watch Series 4 and it's been incredibly interesting. It uses your heart rate to automatically track sleep without you touching the app. So far, I vary from 15 minutes to 1 hour of stage 4 deep sleep per night. The average person needs 1.5-2 hours per night so I am not hitting that. My recent 6 day average is 30 minutes. There is barely a relationship between length of sleep and amount of deep sleep. Just this week I had one night with 6 hours and one night with 11 hours, both totaled 15 minutes of deep sleep. I'd love to compare notes with someone else who uses the AutoSleep app. |