There is a common misunderstanding that all sleep of the same length is created equal; anyone who sleeps for 7 hours will have similar patterns and levels of sleep quality. 

The truth however is that sleep is much more nuanced than that.

Case in Point

Consider the sleep quality of two women from our DOZER database, with similar ages (early 40s) and sleep lengths (7hrs). 

Although both participants slept for the same amount of time, the quality of each person’s sleep was completely different.   Sleeper A scored a ZQ of 66 while Sleeper B scored an 83.

Here, the difference was in the amounts of Restorative and Disrupted sleep:

• Sleeper A had 42 minutes less Deep sleep and 23 minutes less REM sleep than Sleeper B.
• Sleeper B did not wake up at all in the middle of the night while Sleeper A woke up twice and spent over an hour falling back to sleep.

What’s Typical?

Based on past studies, both of these women do have typical ZQs for their age.  The Sleep Age Wheel included with every Zeo shows an average ZQ of 74 for people in their 40s, with an overall ZQ range of 90-66.  They also fall within the typical range of REM sleep and total sleep time.

That said, what could be a terrible night of sleep for one person could be a good night of sleep for another.  If Subject A feels rested and alert with a ZQ of 66, that’s great.  Who knows? Perhaps Subject B feels lousy with a ZQ of 83.  I know it’s been said a lot here on this blog, but sleep is personal.

Where to go From Here

The combination of lifestyle and health factors that affect the way we sleep are numerous and can vary from night to night and person to person.  Perhaps Sleeper A needs to learn some habits to help her fall back asleep faster; perhaps she had a family member that needed attention. 

The suggestions and tips for each of those scenarios vary considerably and that’s why it’s key to take the whole picture into consideration, not just a single metric like total sleep time.

If you’re curious about other peoples sleep, check out our Facebook wall.  A number of Zeo users have posted their sleep graphs there–we’d love to see yours as well!