Sleep Health's Missing Domain
Moving beyond sleep duration to define the systems that make sleep truly restorative
When I began learning about sleep in 2020, and did a deep dive into the neuroscience of sleep and the latest in sleep research, like everyone else, I was focusing on sleep duration, and how much time we spend in different stages of sleep. It felt a bit like reading tea leaves. Why did one night with an hour of deep sleep feel so much different than a different night which also had an hour of deep sleep. What role did REM play? Why didn’t my sleep scores match my daily experience.
Sleep is not a “restful” process, it’s a restorative process. Restoration is an active event. Restoring our bodies and preparing for the next day isn’t “down-time”.
The true measure of sleep quality isn’t measured in minutes, but the functional processes that make sleep beneficial. This is active work is primary driven by the brain. From the glymphatic system flushing metabolic waste, critical memory consolidation work done by sleep spindles, or the protective vigilance of k-complexes, just to name a few. These processes if considered at all, seem like a haphazard disconnected list of metrics that are not tied to any specific measure of sleep.
What is needed is a simple way to discuss these processes, what we call the Neural Function of Sleep. These are processes that we can measure, but also that we can interact with and use and enhance to drive improved health outcomes.
We all understand what cardiovascular fitness is. We don’t have to describe all the individual measures of cardiovascular health, such as blood-pressure, V02-Max, heart-rate, HRV, etc. We have a single term which describes cardiovascular health.
We understand metabolic health, and know that it is more than just our diet, or insulin response. We don’t describe these things based on the individual measures, we have umbrella terms that describes the systems we are measuring or improving.
The current industry approach to sleep, focusing on how much time someone slept, or time spent in a sleep stage, has left us with more questions than answers. We know our sleep trackers don’t match our day-to-day experiences, and we don’t understand why.
We see the industry telling everyone they have to get “8 hours” of sleep, while a huge number of people who reach this “goal” are still asking “why do I feel tired all day”?
Sleep isn’t a score or a measure of time. It’s a complex interplay of hormones, neurotransmitters, and processes all co-ordinating to prepare your brain and body for high function the next day.
We refer to these processes as the Neural Function of Sleep. Though they can be measured, and logged individually, they operate as a system, and only through coordination can they provide optimal health.
Neural Function does not require any special tools. Just like cardiovascular fitness, and metabolic health are available to anyone who is focused and puts in the work.
Much like cardiovascular fitness, and metabolic health, as we age, sleeps neural function naturally declines.
Also like cardiovascular fitness, and metabolic health, we know that some people struggle with achieving the levels of neural function they desire. Often this is due to their lifestyle, such as having young children, or shiftwork, sometimes it is related to other health issues where sleep is secondarily impacted.
Understanding the Neural Function of Sleep allows us to stop obsessing over sleep duration. Instead we focus on the first order processes of sleep which are vital to health. We believe it is necessary to have this frame to measure and more importantly directly interact and enhance the processes which make sleep truly revitalizing.