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The Rhythm of the Night (and Day!)

It won’t always feel like it, but children desperately want to sleep at night! Human-beings don’t just sleep because we have nothing better to do for a huge chunk of a 24-hour period; rather, we sleep because it is a biological imperative. By understanding the processes our bodies initiate to ready us for sleep at certain points, we can manage our child’s waking hours in a way that supports the amazing things their body does to prepare them for a calm bedtime.

Within all of us are a number of biological clocks that link together via a master clock in the brain to manage our circadian rhythm. This then runs in the background of our brain cycling us through each 24-hours, via a series of physical, mental and behavioural changes, priming us for sleep at certain points. Our circadian rhythm is influenced by a number of environmental cues – most notably light, although noise and social habits such as mealtimes play their part also. When combined, these factors help to determine our sleep/wake pattern.

All light on the night

Our circadian rhythm is given a significant helping hand by our body’s production of a hormone called melatonin, which makes us sleepy and improves the quality of the sleep we take. Melatonin is only secreted in low levels of light, hence why we sleep best when it is dark. The body’s ability to produce melatonin is inhibited by light – both natural and that emitted by screens such as televisions, smartphones and tablets. To give your little one the best chance of feeling sleep-ready at bedtime, it is a great idea to avoid having such devices on around a child for at least an hour (ideally two) prior to commencing the bedtime routine.

For similar reasons, the optimal sleep environment for your little one is a room as dark as you can get it: if 10/10 is a total blackout, aim for at least 8/10. As the womb is pitch-black, babies very rarely have an issue with the dark. For an older child who appears genuinely anxious in total darkness, a dim nightlight with a red bulb will produce a comforting level of light without hindering sleep.

Wakey wakey

The other hormone to be aware of in the context of sleep is cortisol. One of the functions of cortisol is to make us feel alert and as its level rises in the early hours of the morning, our bodies begin to drive towards wakefulness. If our little one’s schedule is working well, their cortisol levels will be low in the evening and first two-thirds of the night. However, one important feature of cortisol is that it helps us to “keep going” when we are very tired. When babies have either not had enough daytime sleep, or have been awake longer than is comfortable for them in one stretch, they will have released cortisol to make it through. Whilst this can initially make a little one seem cheery and engaged, the hormone response will, over time, likely leave them either giddy or increasingly cranky. Unfortunately, the more cortisol a little one has coursing through their veins, the harder it is for them to calm down and fall asleep.

One of the few methods a baby has to disperse cortisol is physical movement which is why overtired infants may wriggle and fight being held. Another mechanism for excreting cortisol is through yawning and eye-rubbing and this can often catch parents out – while a single yawn (if spotted!) may indeed be an early sign of sleepiness, multiple yawns and/or an eye-rub are more likely to indicate that the overtired response is already in play and subsequently that the optimal window for getting your little one down has passed. If you notice that your baby becomes irritable at a similar time each evening, or your toddler is often giddy late in the day, it’s a strong sign that their daytime sleep isn’t quite optimised or that bedtime may need to move a little earlier.

Something else to be mindful of is hidden caffeine. While parents wouldn’t dream of offering their tot an early-evening cappuccino, chocolatey desserts contain sleep-busting stimulants which can turn a sweet-treat into a bedtime meltdown!

Feeling hot, hot, hot

Throughout a 24-hour period, the hypothalamus in our brain regulates our body temperature. Our circadian rhythm primes us to sleep when our core temperature is dropping. This means that as a child’s natural bedtime is approaching, the brain will be gradually adjusting their body temperature downwards to make falling asleep easier. It is therefore sensible to avoid particularly energetic play, or other activities which are likely to leave your little one hot, in the run up to bedtime. If a bath or shower is part of the bedtime routine, always check the temperature of the water with a thermometer, both for safety and to avoid inadvertently hindering the body’s bedtime preparations. When the weather is especially warm, you may find that actually reducing the temperature of the water by a couple of degrees helps your little one settle to sleep more easily at bedtime.

Similarly, checking that a baby’s sleep environment is around the recommended 65°F and not overdressing a little one for bed is important – both for great sleep and to keep your child sleep-safe.

The time is right

Almost all children are natural “larks” which means they rise for the day relatively early (typically between 6 and 7am). Consequently, they are ready for bed in the early evening. Most little ones need an overnight sleep of around 11-12 hours meaning that a bedtime between 6 and 8pm is appropriate for babies and young children. Bedtime is far easier for a parent to adjust than a little one’s wake up time which is more fixed due to their lark chronotype, so it makes sense to work backwards from the start of the child’s day to determine the ideal bedtime. When a little one misses their optimum bedtime-window, they have also missed the point when their bodily processes were best aligned to make settling to sleep as stress-free as possible.

The perfect window

The ideal sleep onset latency (time taken to fall asleep) is 15-20 minutes. When a child routinely falls asleep much more quickly, they are “crashing” as opposed to gently drifting down into a deep and restorative sleep via a number of lighter sleep stages. Similarly, a little one who is taking a long time to fall asleep at bedtime and who may also be falling asleep later than is ideal, is limiting the amount and/or quality of the most restful part of the night. Parents should note how long their child takes to fall asleep at bedtime and if it is consistently either 10 minutes or less, or more than 25 minutes, review the daytime schedule to understand where any overtiredness is creeping in.

As you can see, the body is pretty remarkable and initiates a complex series of processes to prime a little one to fall asleep at bedtime. By managing a child’s daytime schedule in a way that supports rather than hinders these mechanisms, a family has taken a significant step on their way to sleep success.

About the Author...

Lauren is a child sleep consultant and founder of Little Sleep Stars. A former tired mama herself, Lauren uses gentle and holistic approaches to help families find their way back to sleep without the process being an ordeal for parent or child. By getting to know you and your little one, Lauren will create a bespoke sleep plan that is tailored perfectly to your child and your parenting style, bringing rest to your family quickly and calmly. You can book a free 15 minute call with Lauren via her website;

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