If you've been doing research on baby sleep, you might've come across the term, "wake windows." This refers to the length of time a baby or toddler can remain awake between sleep periods that they can easily tolerate. Awake time is what helps build sleep pressure (build up of the body’s need for sleep) in babies and toddlers.
Why are there so many varying wake windows guidelines from different sleep consultants?
This is because wake windows are not evidence-based but mainly anecdotal. There is no research that says every baby of a certain age should be up for the same amount of time. Most suggested wake times are just based on averages.
What is sleep pressure & why is it important?
Sleep pressure, or sleep drive, is like the body's way of saying, "Hey, it's time to sleep!" Think of it as a natural signal, and scientists call it adenosine. When we have the right amount of this sleep pressure, it helps us easily drift off to sleep and stay asleep soundly. Sleep pressure builds the longer we stay awake. Sleep pressure is important because it can help a baby/child sleep so much better. The right amount of sleep pressure can help your little one go to sleep easier and stay asleep. Wake windows will help you find your child's "sweet spot" to build the right amount of sleep pressure without getting them overtired.
Overtiredness vs. Undertiredness
Overtiredness occurs when babies & toddlers don't nap enough or stay awake for too long, they can get really tired. When they're overtired, their bodies produce more cortisol (wake-up hormone) and adrenaline, making it more likely for them to resist sleep.
On the other hand, undertiredness occurs when your baby hasn't been awake for long or hasn't had much active play, they might not be sleepy enough to doze off or stay asleep. This is because they haven't built enough sleep pressure to have a good sleep.
Signs of overtiredness:
- Difficulty calming: When a little one is overtired, they are hard to calm down or settle because their bodies have entered a state of overstimulation and heightened arousal, making it difficult for them to relax and settle. When children become overtired, their physiological and neurological systems become dysregulated, leading to increased stress levels.
- Short naps: due to the build up of cortisol in their bodies, it is hard for them to have consolidated and restorative sleep.
- Frequent night wakings: Overtiredness can disrupt the child’s natural sleep-wake cycle, leading to inconsistencies in their sleep patterns and difficulties in achieving a restful and continuous night of sleep.
- Hyperactive: Overtiredness can trigger the release of stress hormones (cortisol), which can stimulate the body and mind, leading to increased energy levels and a state of heightened alertness. After seeming tired or sleepy, your little one suddenly gets a burst of energy and become more lively and active. This is also known as getting a “second wind.”
- Early Rising: Again, due to the disruption of your child’s natural sleep-wake cycles.
If your little one is overtired, instead of stressing in getting them to sleep, work on getting them relaxed and calm. It is easier to assist them to sleep when their bodies are relaxed. Go in a dark room with white noise and do all you can to settle them to sleep. It might also be a good idea to do a contact nap, especially if your little one is dysregulated. This is totally fine & will not ruin your great sleeper. You are meeting them where they are.
Signs of undertiredness:
- Lots of eye-contact, still energetic, happy & alert: Not tired enough for sleep.
- Calm then gets restless in the cot/bassinet: They're initially calm when you put them in their cot/bassinet because they're not that tired, but then get restless as they struggle to fall asleep due to the lack of sleep pressure.
- Takes longer than 20 mins to fall asleep: If they aren’t getting enough awake time, they won’t have enough sleep pressure to go to sleep.
- Short nap, but happy post-nap: only napping less than 45mins because of the lack of sleep pressure. This prevents them from staying asleep. However, they are usually happy after their short nap.
- Early rising, false starts & split nights: These can start to occur if your little one is having too much day sleep or not having enough awake time.
Wake Windows Guidelines:
Whilst all babies are different – and should be treated differently – biologically they do all typically follow a similar pattern. The duration of a wake window can vary among babies, particularly as they transition into young toddlers with changing sleep requirements. Additionally, wake windows may also differ as babies reach various developmental milestones (sitting up, crawling, standing up etc).
When do wake windows start and end?
A wake window starts from the moment you get them out of their cot and stops from the moment you place them in their cot (regardless of what time they have fallen asleep).
If your little one is having trouble falling asleep at bedtime or during naps, I can assist you. I have 1:1 support available, where I'll guide you on how to break the cycle of sleep struggles. You and your baby deserve a more calm bedtime and better quality sleep. I'll educate you on how to understand and support your child's specific needs in different stages of their development. You'll receive a personalised, easy-to-follow plan to help your child sleep better and promote overall well-being for your family.