Baby Sleep Cycles Explained

Have you been asking Google questions like this?

“Why is my baby waking up all night? I just fed her!”

“Why does my baby take short naps?”

“Why is my baby restless in the early morning?”

Let’s stop the scroll and let me help explain what’s going on… 

Your Baby is Having a Hard Time Connecting Their Sleep Cycles.

Their what?!?!  

In a super easy-to-understand way, let’s chat about basic sleep science. This will help you understand why the wake-ups are happening. We will also give you some tips on how you can help your baby learn to sleep longer.

Sleep Cycles & Stages

Each night and nap is made up of a series of sleep cycles, which vary in length based on age.  Sleep cycles are made up of different stages of sleep, which are outlined below.  Each of the stages of sleep has a unique role in brain and body restoration.

There are two primary categories of sleep stages:

REM – rapid eye movement which is when we do our dreaming.

Non-REM – non-rapid eye movement sleep that progressively gets deeper.

The sleep stages include:

Stage 1 – Non-REM:

• Lightest stage of sleep where we are transitioning between being awake and falling asleep
• We are aware of our surroundings
• Very easily awakened 
• Breathing occurs at a regular rate

Stage 2 – Non-REM:

• Sleep is beginning to deepen, yet this is still a lighter stage of sleep
• Relatively easy to be woken up
• Our breathing and heart rate begin to slow and our body temperature drops

Stage 3 & 4 – Non-REM:

• Deepest sleep
• Difficult to be awoken
• When our babies grow, the body repairs and the immune system is strengthened

Stage 5 – REM:

• Dream sleep
• Our bodies are paralyzed so we can’t act out our dreams
• The exception is our eyes and our breathing muscles, which remain active
• Breathing rate can be erratic and irregular
• This is when the brain processes and synthesizes memories and emotions. These activities are crucial for learning.

How Do Sleep Cycles Affect Our Baby’s Sleep?

This chart shows the sleep cycles in a typical night of sleep for a baby.  Below we’ll explore what’s happening during the night, early morning and for naps and provide tips to improve common sleep challenges.

Night Sleep

As you can see in the chart, babies cycle all night long through the different sleep stages and these stages make up a sleep cycle.  This means that in the beginning part of the night, there is a lot of deep sleep so it isn’t as common for our babies to wake during this time. 

Then around 10:30-11:00 pm, the sleep cycles begin to have more REM and light sleep.  Sometimes when your little one is trying to transition to the next cycle of sleep, they come into a light sleep stage and your baby may cry out, fuss and move around. We rush in and say “I want to settle her before she gets upset.” But your little one might not even be awake! If you rush in there, you will likely fully awaken your baby and then have to go through the process of resettling your little one.  I call these battle cries – battling to transition to that next sleep cycle!

When your baby switches sleep cycles and they come into light or REM sleep, your little one is more likely to fully awaken. If your little one doesn’t have self-soothing skills, your baby may wake up and call for you for help to resettle them to sleep. 

Night Sleep Tips:

1. Pause and observe.  If your baby is calling out, but they aren’t due for a feed, pause before rushing into the nursery.  If your little one isn’t fully awake and they are in the light sleep stages, if you go in, you will fully awaken your baby.  Pausing and observing gives your little one the opportunity to surprise you with their ability to resettle themselves!
2. Put your baby down awake at bedtime.  Teaching your baby to fall asleep without your assistance will help your little one to resettle themselves during brief arousals throughout the night. This is one of the major things that we help parents with when we work with them one-on-one.  

Early Mornings

In the early morning, the baby’s sleep cycles are primarily light sleep and REM sleep.  This is why our babies may be more restless in the early morning and have brief arousals before settling back into sleep. 

This isn’t a sign of a problem, but rather just a normal response to transitioning sleep cycles with lighter sleep in the early morning. 

If your baby doesn’t have the ability to resettle themselves independently, you may find that you experience a lot of full wake-ups after 4 am that require a lot of soothing to return to sleep. Or your baby may wake and not be able to get back to sleep.

Early Morning Sleep Tips:

1. This is another time that you really want to pause and observe before rushing into the nursery.
2. Set an ok to wake time in the morning. Normal wake time for babies is in between 600 – 7:00 am, with the average being between 6:00 – 6:30 am.  Find an age-appropriate wake-up time that works for your family and set that as the earliest time that you will take your baby out of their room. 
3. Ensure that the nursery is pitch black.  In the spring and summer months, the early morning light can affect our sleepy hormone production (melatonin). Even a little bit of light can make it difficult to fall back asleep.

Short Naps

An average baby’s sleep cycle lasts between 30-45 minutes.  If your baby consistently takes 41-minute naps, that is likely their sleep cycle length.

What this means is that your baby hasn’t learned how to link their sleep cycles together.  Short naps are extremely common with babies that don’t know how to put themselves to sleep without help. To ensure naps are restorative, we aim for both the morning and the afternoon naps to be at least one hour.

Short Nap Tips:

1. Begin working on teaching your baby to learn to settle to sleep at naptime without your assistance.  Putting your baby down awake will give your little one the best opportunity to switch from one sleep cycle to the next to lengthen their nap.
2. Ensure that the nursery is pitch black.  Light affects our sleepy hormone production (melatonin) which can make it even more difficult to make the transition to a new sleep cycle for longer naps.
3. Begin instituting a crib hour, where you give your baby time to resettle to sleep when they wake up after one sleep cycle.  For example, if your baby sleeps 41 minutes, you would give your little one an extra 19 minutes to try to fall back asleep. 

If you need help teaching your little one to link their sleep cycles for more consolidated, restorative sleep, sign up for a free intro call today.  Our team of experienced sleep consultants offers one-on-one sleep consulting services to improve sleep for a happy, healthy and well-rested family.