Understanding How Your Baby Sleeps: The Key to Better Naps and More Overnight Sleep
If you’re reading this, chances are your kid’s not sleeping so great, so what I’m about to say might make you literally LOL, but I’m going to say it anyway:
God designed us to sleep.
More than that. God designed us to want to sleep.
We come out of the womb with a strong desire and need for rest — we just need a little help figuring out how to do it.
There’s a ton of bad advice out there about getting your kid to fall and stay asleep, but I think the best place to start when your child is struggling with sleep is to look at the incredibly powerful, divinely concocted chemical and biological magic going on behind the scenes.
Here, I give you a quick glimpse at the science of sleep, and I pray that it underpins the instincts you already have and helps you and your child get the rest you both need.
Let’s get started.
The stages of sleep
Regardless of age, everyone sleeps relatively the same way, cycling between REM and no-REM sleep. REM stands for rapid eye movement, which refers to the active and lighter stage of sleep.
Babies spend around half of their sleep in active REM sleep (that’s why they make so. much. noise.); adults spend significantly less time in active sleep (around 20-25%). Furthermore, a baby’s sleep cycle lasts only 45-50 minutes, whereas an adult lasts 90-110 minutes. As an adult, you enjoy long, luxurious stretches of sleep, and your body can keep you asleep as you drift between sleep stages.
Here’s a visual of your baby’s sleep cycles from bedtime to when they wake up in the morning.
All that time spent in active sleep (and all the twitching, grunting, and squeaking) and the shorter sleep cycles make it very easy for them to wake up when they aren’t supposed to. Active sleep also ramps up as morning draws nigh, which is one of the main culprits behind early rising and nighttime wakings.
You may not even realize how often your baby is awake throughout the night (no small blessing), but other times, their inability to pass calmly through their sleep cycles elicits a screech that wakes the whole house.
Meet the circadian rhythm
“Circadian” means “approximately one day,” and if you’ve heard it, someone probably referred to “circadian rhythms,” and the conversation was likely about sleep.
We experience many circadian rhythms throughout the day as we undergo the various physical, mental, and behavioral changes that occur in a 24-hour cycle. But the one I’m most concerned about is the circadian rhythm that dictates sleeping and waking.
We are all born with an immature sleep circadian rhythm that randomly distributes sleep and wake times throughout the day. That sleep rhythm develops quickly, consolidating the cycles after the first couple of months until it’s fully matured in adulthood, allowing for long stretches of wake time during the day and sleep at night.
A mature sleep circadian rhythm plus a consistent bedtime equals a strong sleep compulsion. When everything lines up, your body’s biological and chemical systems work together to make falling and staying asleep easy.
Say hello to “sleep drive”
Sleep circadian rhythms and sleep drive are the twin pillars upon which your child’s nighttime sleep stands. Sleep drive (or sleep pressure) begins to build the moment you wake up. Adult sleep drive builds all day long and peaks just before lights out and when your body’s biological and chemical systems are priming you for sleep. Sleep drive lessens as you sleep and is weakest in the hours just before you wake up.
Your child’s sleep drive builds in the spaces between naps and before bedtime, so schedule management is crucial.
If your child’s sleep drive is an empty cup, you must be careful how much you pour into it.
Too little in the cup, and your child won’t have enough to sleep soundly; too much, and their cup overflows in a sticky, overtired mess. Either way, the result is the same: no naps and/or frequent night wakings and early rising.
Another cave: The sleep drive “cup” isn’t one of those fancy no-spill sippy cups. If it “tips over” during a ten-minute car seat nap on the way home from the store, you can probably kiss that nap goodbye.
What does all this mean for you?
Whether sleep science bores you, overwhelms you, or thrills you, you can’t ignore it, and you can’t work against it. That’s why I think it’s so important for all my clients to have at least a basic understanding of what goes on behind the scenes when their children shut their eyes for sleep.
So, let’s review:
Sleep happens in two stages: REM (active) and non-REM (deep). Your baby spends at least half their time in light, active sleep, making it easy for them to wake up from naps and in the middle of the night.
Your baby enters their lightest sleep stage around 4am
Your baby’s sleep cycles only last about 45-50 minutes, which also contributes to short naps and super early mornings.
Your baby’s sleep circadian rhythm is immature for the first couple of months, which contributes to day/night reversals and poor sleep.
Your baby builds up sleep drive throughout their waketimes, and it’s crucial to give them just enough to ensure easy settling and solid stretches of sleep.
Your baby can often pass through sleep cycles with a few grunts and groans, but ultimately, a time is coming when you need to teach them how to link sleep cycles together with independent sleep skills.
You don’t have to be a sleep nerd to use science to your advantage. Just keep these key points in the back of your mind as you observe your child and their sleep habits.
Are they waking up every 45-50 minutes after you put them down for a nap? They’re probably not making it through sleep cycles independently, or they could have too much juice in their sleep cup (i.e., they’re overtired).
Is your baby taking forever to fall asleep? There’s likely not enough juice in their sleep cup (i.e., they’re under-tired).
Understanding the science of sleep makes a gray situation a bit more black and white. And the best part is that you don’t have to figure it out alone. I’m here to guide you through every step of the process and help you diagnose what’s putting up roadblocks in your child’s sleep patterns.
Let’s talk about your child’s sleep struggles and find a sleep package that fits your needs.
