The Science of Sleep

Last week I discussed “Montessori” Approaches to Sleep and promised to follow-up with some more information about hormonal sleep windows. Hormonal sleep windows are important to understand not only for children, but for adults as well, as ignoring our bodies’ biological needs can have devastating consequences beyond having a hard time falling asleep. Even if your child has a great sleep routine now, its good to understand the basics of “sleep science” as their body’s rhythms and sleep needs will adjust and chance with time, and you want to be able to be one step ahead.

Peasap – Sleep Like a Baby

Bedtime

A lot of people emphasize specific bedtimes for children, and stress that your child needs to have the same bedtime every night — I’m going to just go ahead and tell you, that’s completely unfounded. A child’s bedtime needs to be based on the sleep cycle that preceded it, so if your child’s nap fell earlier or later, or if they woke up earlier or later than usual (in the morning or from a nap), their bedtime needs to be adjusted accordingly.

But why is this?

Hormones

While our children are peacefully sleeping, seemingly at rest, there is a lot going on underneath the surface. Sleep is when all of our bodies grow, repair, and make new connections. If you’ve ever heard the phrase, “Sleep on it,” its not just because time gives perspective, but our brain makes additional connections between various memories (information) while we’re sleeping, so we are more likely to come up with “new” information, solutions, or ideas after we give our brains that chance to rejuvenate.

Deep sleep is also when growth hormones are released, which helps children’s bodies grow and repair. Deep sleep can only occur if the child is relaxed and not producing cortisol.

Cortisol is the “awake” hormone, and its activated by light. Melatonin is the “sleep” hormone, and its activated by darkness. Its so simple but perfect, but children’s bodies need time to adjust to the expectations of darkness, so using lowered or minimal lighting for the hour or so leading up to bedtime can help ease children’s bodies into sleep.

Routines

I stress how important bedtime routines are, and while “relaxing” activities are great, the main purpose is to create a chain of events that your child’s body identifies as culminating in sleep. I think its important to pay attention to your child with this and notice which activities are relaxing for them, and which just energize them all over again! For example, I can’t tell you how many people and blog posts have said that a bath and books before bed are their go-to routine — well, they don’t have my daughter.

Miss G loves cold baths, which just awakens her nervous system, and gets really wrapped into the storyline of any story that we read before bed. Reading the same stories every night are a safe bet, but even better, I have two reusable sticker books that she explores until she can barely keep her eyes open.

Cortisol and the importance of a soothing sleep ritual are two reasons why I personally have never tried cry-it-out. A child who is upset and crying is going to be creating cortisol — and adrenaline — which is going to disturb his or her ability to get into deep sleep cycles; any form of emotional upset or stress will have a negative effect on sleep. There are many ways to encourage children to self-sooth without resorting to cry-it-out.

 Napping

I know a lot of people who think that they need to start cutting out naptime if their child is consistently having later bedtimes, when actually, naptime might just need to be adjusted in length or timing. Ironically, a difficult time falling asleep is usually linked to being overtired. In many cultures, naptime never ends — even grown-ups take part in the ritual, so there is no hard and fast rule about when naps should end.

Rather than looking at bedtime as an indication of whether or not the naps should be cut out, look at how your child behaves in the time leading up to naptime. Does their body naturally start to wind down? Do they exhibit whininess or overtired tendencies? If you’ve already tried skipping a nap, how did your child act during the naptime, or time after when it would normally have been?

Despite popular belief, children cannot “catch up on sleep.” So if a child stays up late for a special event, even if they sleep in the next morning, they are still operating on a sleep deficit. This is part of why it’s so important to protect bedtime and sleep routines. I had a really hard time with this when I had to work shifts that ended after Miss G’s bedtime and my parents who were generously helping watch her, were not willing to watch her at my home and put her to bed. When I was able to work from home and put her to bed at an earlier time, I noticed a huge behavioural shift and Miss G seemed to have a lot more energy than she did on our previous sleep schedule, despite getting the same amount of sleep.


I’ll follow up on this post with some ideas about how to set up an ideal sleep environment, and tools to help with bedtime, but for now, what are your sleep questions?