THE 4AM WIDE AWAKE CLUB

Why is your little human wide awake at 4am? Find out the common reasons, how to overcome them and why you’re not alone!

One of the biggest issues I see as a sleep consultant is increased wakefulness towards the end of the night, especially from 4am onwards.

Obviously babies wake up all throughout the night as part of normal sleep, or due to a whole host of reasons such as hunger, poor sleep hygiene, sleep associations, lack of routine and over tiredness. 

But why is the phases between 3 and 5am often hardest for babies and toddlers to stay or fall back to sleep? 

Sleep Science

Our sleep/wake cycle is governed by a delicate balance of systems within the body to keep us awake during the day and asleep overnight. Firstly, sleep drive, or pressure, dictates the balance between sleep and awake using a process called homeostasis, a state of equilibrium between different elements of an organism. The longer we are awake, the greater the sleep drive, which in turns reduces gradually as we sleep.

If just sleep drive alone were in control of our sleep, we would feel increasingly drowsy throughout the day, rather than having peaks and dip as we actually do. Alongside the homeostatic sleep process, our sleep is also governed by our inner body clocks known as our circadian rhythm, which are largely controlled by sunlight, and so most of our body clocks roughly follow the pattern of the sun. But how does it know when its light and dark?

Within the brain, a group of cells in the hypothalamus called Suprachiasmatic Nucleus (SCN) respond to light and dark signals. When light (and in particular, blue light) hits special receptors in the eyes, it sets off a chain reaction to release or suppress hormone production which controls our sleep drive, hunger, and body temperature. As it gets dark, the SCN produces the sleep hormone melatonin, helping to reduce our body temperature and promoting sleep. Towards the end of the night as it gets lighter, melatonin production is suppressed, and instead cortisol is released increasing our alertness and helping us wake for the day.

Light

As we’ve seen, light is the biggest influential factor on our body clocks, so it’s no wonder that light exposure at the wrong time can play havoc with our sleep/wake cycles. Whether it’s screens, artificial light or sunlight, monitoring your child’s intake of light is key to maintaining their body clock rhythms.

The number one thing to help your child’s body clock is to be in control of when they exposed to light and dark. This not only helps keep them on track, but it also helps to get back on track, for example after a holiday or a the clocks changing.

It can be hard to keep sunlight at bay, especially as it’s getting lighter towards the end of the night. During the summer, a good black out solution is a must for the large majority of babies and children to help their body clocks remain on schedule.

Limit screen time in the run up to bedtime and ideally have at least an hour of dark time before they are due to sleep – keep artificial lighting to a minimum (lamps with a blue light filter are a bonus). For younger ones, darkening the bedroom after bath is usually enough to wind them down and give sufficient cues to the SCN. If you are having particular wind down or falling asleep struggles at bedtime, extend their wind down time and dark exposure further.

Instead of tv and tablets near bedtime, encourage them to play with puzzles, and toys that don’t emit light, plus colouring and reading can be great for winding down at the end of the day. Plus most children learn to drag out bedtime for as long as possible so the large majority of the ‘dark hour’ will be spent getting them through the bedtime routine!

Lightest sleep phase

Once a baby reaches around the age of 4 months (yes the dreaded 4 month sleep regression!), their sleep is reorganised into a more adult-like way of sleeping. There are 4 distinct phases of sleep, with REM sleep being the lightest, and subsequently the most easily disturbed phase. As you can see from the graph below, the majority of REM sleep occurs in the last few hours, coinciding with other difficult factors for sleep from 3am onwards.

So sleep is always going to be harder to maintain during this light sleep phase, and whilst there’s not much you can do about the physiology of sleep, it’s worth knowing that it’s an influencing factor around this tricky time. The good news is that there are plenty of ways to improve REM sleep including:

• increased daily exercise – help your child expel their energy during the day and get as much fresh air as possible
• sufficient hydration – make sure your child has plenty of water throughout the day, though not just before bed as this can disturb sleep with overnight bathroom trips)
• a good sleep schedule – develop a consistent routine so that your child’s body clock knows when it’s time for sleep
• create an ideal sleep environment – see the other points on light and temperature
• watch their diet – avoid sugary foods and drinks in the run up to bedtime, and for older ones, the same goes for caffeine too

Gut issues

During sleep, much of our body shuts down to repair and replenish, especially during non-REM sleep. During this sleep phase, the body is calm and still, growth hormones are released and heart rate is slow. Although the body continues to digest food and use it for energy whilst we sleep, it does so at a much slower rate than whilst awake. This effect is even slower in the lower gut, as this is what is necessary to stop bowel movements occurring overnight.

Towards the end of the night however, our gut starts to wake up again. During REM sleep, which as we’ve seen already occurs mostly during the final few hours of the night, intestinal function has been shown to increase again. This could explain why many children wake from tummy aches from around 4am onwards. It’s why many babies and younger children may poo immediately upon waking in their nappy because, well, why wait any longer! In fact, with the many babies I’ve looked after overnight, almost all have suffered worse between 3am and 5am with trapped wind, reflux and other digestive-related issues. This was also confirmed by Dr Neil Shah, a paediatric consultant specialising in reflux and allergies, and who I learned a great deal from during a course I attended back in 2017.

If you’re finding your child is struggling at this time of the night, it may be worth checking you’re doing all you can to improve their gut health whilst they sleep. The primary focus overnight should be restoration, but if there are tummy troubles, their stomach may continue to churn when they should be sleeping peacefully. This includes eating a healthy, fresh, balanced diet (crucial for sleep in general!), in particular lots of fibre, berries, nuts and seeds, and stick to more easily digested foods towards the end of the day (there’s a great infographic here for how long digestion takes for a multitude of foods) so that the stomach and lower gut isn’t full of undigested foods the whole night.  Probiotics are great for the microbiome and have been shown in recent years to also have a positive impact on sleep, though this area of research is still fairly new. It’s also worth avoiding sugar, caffeinated/fizzy drinks and processed or high-glycaemic index foods, especially in the run up to bedtime.

As for the timing of eating, their last big meal should be around 2 hours before bedtime, allowing enough time for digestion before they enter sleep. For little ones in nursery that have an early dinner and may be hungry, check out our blog for the best bedtime snacks to induce sleep.

Lastly, drinking plenty of water can help ease the digestive system both day and night.

Less sleep pressure

Although most babies and young children need at least 10 hours sleep overnight, by 4am they’ve often had the large majority of their sleep. Alongside cortisol levels rising, sleep pressure is reducing the more we sleep so in the last 2-3 hours before morning time, sleep pressure is far less than in the first half of the night. As we need enough sleep pressure to continue sleeping the entire night, we need to do all we can to ensure that the sleep pressure is at it’s greatest just before we head to bed.

This is usually trickiest for younger children, in particular those that are still napping or are prone to nodding off late in the day, as daytime sleep can disturb the build of adenosine, the sleep pressure hormone.

Try to avoid any sleep in the last wake window before bed – for babies this is likely to be in the last 2-3 hours of the day, whereas toddlers and pre-schoolers often need 4-6 hours minimum awake time before building up sufficient sleep pressure to maintain a full nights sleep. For some children, this includes even a just a few minutes of sleep, including falling asleep during the last feed of the day and then being put down awake, or having a quick snooze on the way home just before dinner/bedtime. Sometimes of course this can’t be avoided, but if you’re having trouble keeping your child asleep beyond 4am, and they are regularly having sleep too late in the day, it’s worth trying to adjust their day wherever you can to improve their sleep pressure towards the end of the night.

Coldest part of the night

Not only does our body temperature drop at this tricky 4am time, so does the environment. Our core body temperature can drop by as much as 2 degrees overnight, decreasing as melatonin production increases as we sleep, reaching it’s lowest temperature a few hours before waking. Most homes also drop in temperature overnight no matter the season, and again, they are usually at their coldest towards the end of the night. 

The correct temperature is vital for sleep, as studies have linked overheating with many physiological sleep disorders including insomnia and night terrors. Plus if your environment is too hot or too cold, your internal thermostat is going to be working extra hard to get it where it needs to be.

So what’s the ideal room temperature for sleep? Ideally not too hot or too cold, and it varies from child to child too. Some children are hotter than others, so … Babies sleep safely between 16 and 20 degrees, but a similar range can also be conducive to sleep no matter what the age. 

If your child is a hot sleeper, or your house runs warm, opting for breathable, cooling nightwear and sheets made from natural fabrics such as cotton, linen and bamboo can help. Avoid baths and showers that are too hot or cold in the run up to bed as this can alter the body’s core temperature and offset their body clocks working hard to make them sleepy. Lastly, over-exertion or exercise can cause elevated body temperatures so allow your child ample time to recover if their routine includes a late activity or nursery pick up.

If you’re struggling with sleep, get in touch for a free 15 minute assessment call to find out how I can help. You can also sign up to the HushaBoo email updates to be the first to find out about future blogs. Or follow HushaBoo on social media…