Things to do before the school year starts:

• Buy school supplies
• Buy school clothes
• Meet new teacher(s)
• Getting kiddo back to a regular bedtime (Yeah, about that…)

It’s not easy getting your kid back into routine after summer vacation, especially when sunset is well past 8pm. There’s a reason for that. It’s the same reason we feel energized, tired, or hungry throughout the day. It’s our circadian rhythm.

Rhythm is Gonna Getcha

Directly influenced by environmental cues, circadian rhythms are 24-hour cycles that operate as the body’s internal clock. They are responsible for carrying out the body’s daily tasks to ensure that we function at our optimal levels throughout the day. They dictate our energy levels, sleep/wake cycles, appetite, and bodily functions.

Light is the most powerful influence on our circadian rhythm. This is because our circadian clock is governed by the SCN (aka suprachiasmatic nucleus), a group of cells in our hypothalamus (region in the brain that regulates autonomic functions) that are extremely sensitive to light. When our eyes detect light in our environment, the visual system relays this information to the SCN which triggers a chain reaction of hormone production and suppression to keep us regulated throughout the day.

A 24-hour cycle can look like this:

• As the sun rises, so do our body temps and cortisol levels (the stress hormone), increasing our alertness to wake up and get out of bed.
• High and low arousal levels occur in 90-minute cycles. It may take a couple of hours to reach optimal alertness and energy; but once achieved, it will slowly decline and hit a low in the mid-afternoon (between 1-3pm).
• Alertness increases again around dinner time (5-7pm) but will decrease as the daylight reduces. Melatonin (the sleep hormone) rises as our body temperature lowers, helping to facilitate sleep.
• Our energy levels will gradually drop until it hits its lowest point while sleeping (1-3am), thanks to the elevated doses of melatonin.

Other tidbits about the circadian rhythm:

• The peak of nighttime sleep and daytime drowsiness follows a 12-hour cycle. So, if your kiddo’s bedtime is at 8pm and their wake-up call is at 6am, their peak sleep is around 1am and they will most likely be tired around 1pm.
• If our eyes perceive light, the SCN will suppress melatonin production.
• Other hormones play a role in keeping our body maintained during our waking hours like vasopressin (the antidiuretic hormone), acetylcholine (influences attention, arousal, memory, and motivation), insulin (regulates blood sugar) and leptin (regulates hunger).

Timing’s Off

The sleep-wake cycle is the most important and well-known of the circadian rhythms. As our internal clock syncs up with the day, it can promote consistent and restorative sleep needed for learning, attention, and memory. This is probably one of the reasons why we can become sticklers when it comes to our kid’s sleep schedule. We know firsthand what it’s like to have a terrible night of sleep and how it hinders our work/life balance (limited attention, lack of patience, mood swings, and overall grogginess). The difference is that we can rely on things like caffeine to keep us up and running. Our kids however aren’t ready for this.

If our kid’s circadian clock is disrupted, they may have trouble falling and staying asleep. They might also have shallower, fragmented, lower-quality sleep, which could put them into a sleep debt (the difference between the amount one needs to function and the amount they are actually getting). For example, school-age children should be getting about 9-11 consecutive hours of sleep a night. But if they are only receiving 6 hours, then they have accrued 3-5 hours of sleep debt. You can overcome sleep debt within a day or so by getting in a nap or going to bed early, but regular long-term sleep debt can take a toll on overall health and well-being as you get older.

What can throw off our child’s circadian rhythm?

• Too much light at night. A 2018 study found that bright light exposure of preschool children (ages 3-5) in the evening suppresses melatonin production almost completely, lasting an hour after the light was turned off. Another study conducted in 2015 reported greater light sensitivity in younger children compared to older ones. It also found that the brighter the light, the higher the melatonin inhibition.
  
  
• Poor sleep hygiene. Sleep hygiene is a series of behaviors and environmental setups intended to improve the quality and quantity of sleep. This isn’t just what occurs right before bed, but what takes place during the day as well. That means overscheduling, excessive naps, limited physical activity, or screen time close to bedtime can all have a negative effect on your kid getting good zzz’s.
  

• Time changes. Children are the age group most affected by time shifts, like jet lag or daylight savings time (DST). Darker mornings and more evening light can delay a sleep-wake cycle, making it difficult for our kids to go to bed at a decent hour or wake up when they need to. Additionally, DST results in losing about 40 minutes of sleep. As with any change, the brain requires a period of adjustment to get back into routine.
  
  
• Not syncing with their circadian rhythm. Although schools/educators consider the effects of  circadian rhythms in their daily class schedule (movement breaks, recess, snack time), it can be difficult for parents to accommodate. A 2013 study found that children having problems settling after their bedtime could be due to parents putting them down before their melatonin levels were high enough to induce sleep. However, when the child’s bedtime synced up to their nightly melatonin release, they were shown to fall asleep more quickly and had decreased bedtime resistance as reported by their parents.

Getting Back in the Loop

Here are some ways to re-calibrate your child’s circadian rhythm in time for school:

• Find the ebbs and flows. Figure out your child’s arousal levels throughout the day. Ask them when they feel the most attentive and most tired. From there, you and your child can plot out a schedule that is most attuned to their internal clock. So, if your kid is tired after school, maybe they need some downtime or could complete a task that doesn’t require much effort. If they are energized, that might be a good time to sign up for an afterschool activity, do their homework, or help with house chores.
  
  
• Help them listen to their body. Although our circadian rhythm is operating in the background of our daily lives, it does utilize our interoceptive system to communicate its needs. Help your child understand the signals their body is telling them to keep their internal clock going. Tummy grumbling? Hungry.  Constantly yawning and droopy eyes? Tired. Pressure on the bladder? Bathroom break!
  
  
• Engage in sleep hygiene, all day every day. What our kids do in the day affects how they’ll sleep at night. How they sleep at night affects how they will engage in tasks and activities the following day, and so on. It’s a cycle, but it doesn’t have to be vicious. Good sleep hygiene should involve:
  • Spending time outside to calibrate circadian rhythms
  • At least 2 hours of physical activity daily
  • Limiting naps, especially in late afternoon/evening (exception: infants and toddlers)
  • Strengthening the association between the bedroom and sleep, meaning homework and other activities should be done elsewhere
  • Avoiding heavy meals or sugary snacks prior to bedtime
  • Reducing light exposure about an hour and half before bed (lower blinds, dim lights, screens put away if possible). Patti has a sleep mask when she travels. The twins saw it and immediately wanted their own.
  • Maintaining a consistent bedtime routine

We’ll also stick in a gentle reminder that you also may not have had a morning alarm for the last couple months of summer. A 5 or 6am wake-up followed by school drop off might not be the easiest transition for a parent as well. Make sure you are adjusting your sleep schedule for the first week of school, too.

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