March 19, 2021, is World Sleep Day. To honor this occasion we’ve decided to take an in-depth look at WHOOP members’ sleep from a variety of angles. We break down norms and averages for the many different sleep metrics we monitor based on things like age, gender, location, day of week, and more.
We’ll start with the basics. On average, WHOOP members spend 8:02 in bed each night, which translates to 7 hours and 11 minutes of actual sleep. Women spend more time in bed (8:12) and get more sleep (7:23) than men do (7:57 and 7:06).
As you can see in the graphic above, younger and older people spend more time in bed. Our members in their 30s and 40s spend the least time in bed of any age cohort, right around 8 hours per night.
To no surprise, WHOOP members spend more time in bed on the weekends. They also tend to make more of an effort to sleep to start the week (Mondays) than they do the rest of the week.
In the US, we average 8:01 in bed each night, and 7:10 asleep (slightly below the overall norms). Two European countries with large WHOOP member bases both sleep significantly more: Germans average 8:04 in bed and 7:17 asleep, while in the UK people spend 8:10 in bed and sleep for 7:19.
We refer to REM and slow wave sleep (also known as deep sleep) as the “restorative” stages of sleep. Female WHOOP members spend a higher percentage of their overall sleep time in REM (26.3%) than males do (26.0%), however the reverse is true for deep sleep (21.0% for males, 19.5% for females).
Younger people get a higher percentage of REM sleep than older people do, with the drop off starting to occur in the 30s and 40s and continuing with age.
For the most part, deep/slow wave sleep percentage stays consistent with age, but does fall off as well when people hit their 60s and 70s.
Sleep consistency is a term we use at WHOOP to describe how similar your bed and wake times are on a daily basis. Our research has found immense benefits of sleep consistency, including improved sleep efficiency and more restorative sleep. It also helps maintain circadian rhythm, your body’s 24-hour internal clock that regulates many biological cycles and functions.
Predictably, sleep consistency improves with age. WHOOP members under 30 have much worse sleep consistency on average than those above.
As you might expect, most WHOOP-member naps occur on weekends (36%, with 18% each on Saturdays and Sundays). If people nap during the week, it’s least likely on Tuesdays and Wednesdays (12% each), with Monday and Thursday at 13% and Friday being when 14% of all naps happen.
While our very oldest and youngest WHOOP members nap the longest, generally speaking nap lengths decline with age in the 30s, 40s, 50s and 60s.
Learn More: How Long Should You Nap For?
When your body doesn’t get all the sleep it needs at night, sleep debt begins to accumulate. The average amount of (pre-sleep) sleep debt for WHOOP members is 43 minutes.
Sleep debt tends to increase as the week progresses, with people “catching up” on sleep on the weekends. Because of this pattern, we see the highest average sleep debt prior to bedtime on Saturdays, and the lowest on Mondays.