Understanding Early Sleep Phases and Why They Lead to Early Wake-Ups

If your baby is stuck in a 5am wake up pattern and even day light savings didn’t shift it, you’re probably getting pretty desperate for some sleep by now.

Early wakes are one of the hardest sleep challenges to solve, and many parents end up needing a consult with myself or my team to get on top of early wakes. The challenges arise due to the fact that it is the tail end of sleep we are trying to fix.

Imagine you can run a marathon but you want to be able to run the last 1km a little better… That’s what it’s like fixing an early wake up.

Understanding the concept of early sleep phases can offer insight and help set the stage for a well-rested family. As a science-based sleep consultant, let’s break down how early sleep phases work, why they lead to early waking, and how you can address this challenge.

What is an Early Sleep Phase?

An early sleep phase means that your child’s internal clock, or circadian rhythm, is naturally set for an earlier bedtime and, consequently, an earlier wake-up time. This phase is part of a biological rhythm controlled by internal factors like melatonin and cortisol release, as well as environmental cues like light exposure and daily routines. For children in an early sleep phase, falling asleep at 6:00 or 7:00 p.m. may feel entirely natural, but it also means they are likely to wake up around 5:00 or 6:00 a.m.

The Role of Total Sleep Needs and Sleep Drive

Each child has unique total sleep needs, and these needs help regulate what we call sleep drive. Sleep drive is the body’s desire for sleep, which builds up gradually over the course of the day. For children with lower total sleep needs, an early bedtime may result in an early wake-up simply because their body has had enough rest by the early morning. Ensuring that total sleep time aligns with your child’s age and needs can often help alleviate some of these early wake-ups.

Sometimes keeping a log of how much sleep in the day and night your child has for a week can help you to see exactly how much sleep your child is getting. If it is inside the range of averages for that age, and you still have an early wake, it might just be an early sleep phase which we need to shift to eliminate the 5am start.

Sleep Pressure and Sleep Cycles

Sleep pressure, like sleep drive, is the accumulation of a biological need for sleep, building gradually as the day progresses. When a child’s sleep pressure reaches a peak in the evening, they are ready for deep, restorative sleep. Sleep cycles play an essential role here as well; each cycle consists of various sleep stages, including deep, REM (rapid eye movement), and lighter sleep stages. In young children, these cycles are shorter, around 45-50 minutes, which means they experience several cycles per night.

When a child reaches the end of a cycle, they are more likely to experience a partial arousal. If the timing of these cycles aligns with the early morning hours, a child can move out of their deep sleep stage and may fully awaken, particularly if their sleep pressure has subsided. For children in an early sleep phase, these arousals tend to occur in the early hours, making them more prone to wakefulness.

Melatonin and Cortisol: The Hormones of Sleep and Wakefulness

Two critical hormones regulate sleep-wake patterns: melatonin and cortisol. Melatonin, often referred to as the “sleep hormone,” rises in the evening to signal sleep readiness. In contrast, cortisol, the “alertness hormone,” begins to rise early in the morning, helping the body wake up.

In children with an early sleep phase, melatonin levels may peak earlier in the evening, and cortisol levels may start to rise before 6:00 a.m. This early rise in cortisol is one reason children may wake up so early, fully alert and ready to start the day before parents are.

Sleep Stages and Their Impact on Waking

Each sleep cycle progresses through different stages, from light sleep to deep sleep to REM sleep. In the first half of the night, deep sleep dominates, which is the most restorative stage. As the night progresses, REM sleep and lighter sleep stages become more frequent, making children more prone to wakefulness in the early hours.

Children who are in an early sleep phase naturally may complete most of their deep sleep earlier in the night, leaving lighter stages in the early morning, which increases the likelihood of early waking. This pattern can be particularly noticeable if your child’s total sleep needs are on the lower end for their age.

And children who are very tired by the end of the day, that is they have more sleep pressure due to lack of naps, or an early wake, may quickly enter these deep phases of sleep. This compound the issue with early waking as your child comes out of their deep phases of sleep even earlier and thus wake even early in the morning.

Why Early Sleep Phases Cause Early Wakes — and What You Can Do

Early sleep phases are a natural part of some children’s biological rhythms, but they can be adjusted gradually with careful attention to sleep timing, total sleep needs, and consistency. Here are a few tips:

1. Adjust Bedtime Gradually: To shift the early sleep phase, try delaying bedtime by 10-15 minutes every few days. Over time, this can help move their wake-up time slightly later as well. This does need to be done in conjunction with naps so you don’t force your child into a state of extreme over tiredness.

2. Encourage Adequate Daytime Activity: Ensuring enough physical and mental stimulation during the day can help build healthy sleep pressure, contributing to a more robust sleep drive at night.

3. Limit Morning Light Exposure: Light exposure suppresses melatonin, so reducing morning light can sometimes help delay wakefulness. Use blackout curtains to prevent early morning sunlight from signaling that it’s time to wake up.

4. Shift nap timings to end later in the day, reducing sleep drive earlier in the evening, and allowing for bed time to move later, and your child to be less tired at bed time and take longer to get into those deep stages of sleep.

Understanding your child’s early sleep phase can help you work with their natural rhythm rather than against it. Adjusting this rhythm takes time, but with a steady, science-backed approach, you can create a sleep routine that supports both your child’s needs and your own.

I mentioned earlier early wakes are hard to resolve, but we are really good at coming up with a plan that addresses the root cause of why you have an early wake.

• Over tired.
• Under tired.
• Early sleep phase.
• Lack of daylight exposure.
• Long morning nap.
• Inappropriate nap times.
• Too much nap time.
• Lack of day sleep.
• Nutrition.

These are all factors which we look at when we work out an early morning wake up plan.

If you think you need to speak to us about early wakes, try our 30 minute consult. It is a one off consult which is perfect for one off problems such as early wakes.

See our 30 minute consult page for more information on how to book in.