We have all experienced it, that moment when the alarm goes off and we wearily fumble the touch screen or pound the snooze button. At a certain point however, we can’t keep hitting snooze and we have to get up and get out of bed. What we experienced is called sleep inertia, the transition time from the moment you were woken up - when that alarm went off - to the point in time that you decide to wake up fully and engage the day.
This time can be a mere matter of minutes and for those who don’t struggle with sleep inertia related problems, it is a quick ordeal. However, this can drag on. It’s normal for this feeling of still being more invested in sleep than being awake to last up to ten minutes however it can in certain individuals persist for upwards of several hours.
This state of being is not pleasant. Your body is leaving its place of healing, restful and restorative sleep and your brain isn’t wanting to come to grips with that. You spend your duration in this in between land having trouble thinking clearly and depending on the duration of this time, it can cause frustration and pose problems for getting your day started.
The name is indicative of why your body is in this state as inertia is the state at which something does not change unless it is acted upon by another force. In this case, your sleeping brain doesn't want to change into your wakeful brain.
Your Body Switches Into New Territory While Sleeping
Our bodies love to sleep however sleep is a very complicated process. When we lay down to rest it’s not just our muscles that are transitioning into a different state of excitement and relaxation but our central nervous system.
The central nervous system is responsible for coordinating all of our bodily movements and states of being. It’s responsible for communicating all of your daily needs so that you know when you’re hungry, tired, sleepy, sad or in physical pain. It is also the key player in how we sleep and the quality of that sleep.
Our bodies do incredible things while we are sleeping to not only boost our health but keep us safe while we do. During REM, one of the four phases of a sleep cycle, our brains are actually very active and this is when we would remember our most ‘vivid dreams’. Because our brains are so active (REM stands for rapid eye movement), our central nervous system actually temporarily paralyzes our muscles to keep them from acting out our dreams!
On top of this our bodies reduce in temperature, lower cortisol levels (stress hormone that is associated with high alertness, and even release certain hormones that help us not have a bowel movement or urinate while we sleep.
What Could Be Causing Sleep Inertia
The exact causes behind sleep inertia aren’t fully understood and are still being investigated. However, it has been theorized that the most plausible reason for sleep inertia is when you wake up during your sleep cycle.
When you sleep, your body enters into a cycle that is composed of four phases and every phase has a different purpose and effect on your body. These four phases are divided into two categories called non-rapid eye movement (N1-3) and rapid eye movement (REM).
The first three phases of sleep, N1 through N3, are all located from the time you fall asleep to the moment of your deepest slumber. The total duration of these three phases varies from person to person however it averages forty to sixty minutes. During these phases, aside from the initial drifting off to sleep, you probably won't have a lot of memories.
During the last phase, and what scientists are finding out is one of the most important phases of sleep, you experience your REM sleep. This is the point in your sleep where your brain becomes the most active, and you will probably remember dreams from this period of sleep as well. During your sleep cycle this is also the time that you have high levels of melatonin that have a GABAergic effect on your central nervous system keeping it calm and chilled out.
It’s during this phase, the REM cycle, that problems with sleep inertia are thought to originate. When you are not given the proper time to move through the entire REM phase, but instead are woken up out of it, sleep inertia is thought to become a problem.
Melatonin is Mellowing Me Out
It is thought that melatonin is a primary culprit for this, as your central nervous system will have a rather high amount of melatonin still actively circulating during REM sleep. Not only melatonin but also adenosine, an amino acid associated with sleep is also thought to be at high levels during this time of sleep.
But why do these chemical compounds matter and how do they affect you? The central nervous system has two main methods or pathways of helping you feel alert or sleepy and tired. These pathways are the GABA and Glutamate pathways.
GABAergic molecules or chemical compounds are going to be substances that trigger GABA receptors to push these pathways forward leading you to calm down, chill out and even get sleepy. This pathway is thought of as an inhibitor pathway. Glutamate does the opposite and helps the body become more heightened and aware.
When we wake up and these chemicals are still at high levels in our central nervous system, it is thought to cause us to feel that groggy, foggy and unpleasant sensation of continuing to wake up for a prolonged amount of time. This is what we call sleep inertia.
What Are Some Options For Helping You Fight Sleep Inertia
The truth is, you may be doing everything you possibly can to help get a fulfilling, restful night of sleep, but that wont much help with your struggle against sleep inertia. Thankfully, there are some things you can try out!
Chances are, if you have experienced symptoms related to even mild sleep inertia, you are already familiar with this popular remedy. Caffeine acts as a stimulant in the mind, propelling your brain forward and actually acts as an adenosine antagonist blocking it’s sleepy effects. While it isn’t a strong stimulant that gives you energy, it promotes your body's natural alert and awareness pathways encouraging wakefulness.
A Cold Shock of Water
This method has been used for probably as long as humans have been dealing with sleep inertia and that should speak for itself. While it may not have long lasting effects, washing your face with cool water or taking a cool shower can help to jolt your mind into a place of more alert readiness.
Melatonin Free Sleep Aids
Our bodies naturally make melatonin and this GABAergic compound helps us feel sleep and enjoy great sleep. However, it is possible that supplementing melatonin can have an adverse effect of causing unwanted drowsiness. Supplements that instead use ingredients like L-Tryptophan, a natural amino acid that acts like a Glutamate antagonist that blocks your wakefulness pathways but doesn’t ‘enhance’ your sleepy or drowsy pathways could be a great option.
Meet our Experts
This article has been reviewed by members of our Scientific Advisory Board.
Dr. Jay Cowin, Nutrition Expert
Founder of Functional U, a Nutrition, Performance & Optimal Health practice.