Why is reaching 90% sleep efficiency so important?

You can’t hit 90% all the time, not even good sleepers do this. Try not to look at hitting 90% and so adding time to your sleep time as the end goal, the goal is to get your body used to your new schedule (generated by your first week of sleep diaries) and become consistent with it.

Your sleep efficiency is literally just comparing your sleep time and time spent in bed and seeing whether they are similar. The closer they are, they higher your sleep efficiency will be. When you start making your schedule more restrictive because you want more consistency in your sleep, it is harder to hit that 90% every week.

We can also hit a plateau. Usually this means that we have done the hard work and now our bodies will take a bit longer to see the same kind of results. This is completely normal but this stage demands patience. Also remember that there are so many factors that affect our sleep, it would be impossible to always meet 90% sleep efficiency as we cannot control all the variables in our lives.

When you get to your first 90% week, it means you have never slept more consistently whilst being on the course. You’re getting your total sleep time fairly regularly. Don’t worry about how long it takes you to get there - getting to 90% sleep efficiency is amazing progress.