Circadian rhythm and toddlers: Understanding their sleep cycle for better movement and development
You’ve probably heard the phrase “circadian rhythm” thrown around, especially when your baby was first born. We hear in the beginning that babies aren’t able to distinguish between day and night, so all the baby books suggest various—and sometimes contradicting—tips to help regulate babies’ circadian rhythm.
But what does this actually mean? And, what does it mean for your baby as they grow into a toddler, begin to have more consistent sleep patterns at night, and are also much more physically active during the day? Let’s learn more about circadian rhythm and toddlers.
What is circadian rhythm?
Circadian rhythm is our body’s natural 24-hour cycle that regulates sleep, wakefulness, and other physiological processes. This internal clock responds to external cues like light and temperature, helping us feel alert during the day and sleepy at night. For toddlers, whose bodies and brains are rapidly developing, a well-regulated circadian rhythm is important for their physical and mental health.
But how can you actually help your toddlers regulate something like this and create a healthy circadian rhythm for changes in their routine and expanding physical capabilities as they grow into preschoolers and young children? We’ll cover more of this in a bit.
Circadian rhythm and toddlers’ bodies
By six months, your baby should have a regulated sleep pattern, and their little bodies should start to have an idea of day versus night. But the reality is much different, and for some children, sleep time is a struggle for much longer than that. Do you have a toddler who wakes up the minute the sunlight creeps in in the morning, even if it’s only 5 a.m.? Or a toddler who won’t sleep until it’s perfectly dark outside? While this might be bad news for the parents, it’s good news that your toddler has a strong circadian rhythm.
Why is this important? By the time your baby grows into a toddler, their growth may have slowed down, but they’re still growing taller and gaining weight at a pace of up to 2.5 cm a month! They’re learning to expand their gross and fine motor skills, from scribbling with writing utensils to running, jumping, and climbing.
The importance of sleep patterns on physical activity and growth
The alignment of a toddler’s circadian rhythm with their daily activities can have a profound impact on their development and movement. Adequate sleep ensures that toddlers have the energy to engage in physical activities, which are vital for their motor skills and physical health. Regular physical activity, in turn, helps regulate their circadian rhythm, creating a beneficial cycle.
Additionally, sleep itself should also be thought of as physical activity. Even though we’re resting, it’s imperative to your toddler’s health. These are just a few things that happen to your child’s body while they’re sleeping:
- Release of the growth hormone: A significant amount of growth hormone (GH) is released during deep sleep, particularly in the first few hours of sleep each night.
- Tissue growth and repair: GH stimulates the growth of nearly all body tissues, including bones and muscles. It also plays a vital role in tissue repair, helping the body recover from daily activities and minor injuries.
- Bone elongation: Growth plates at the ends of long bones are areas of new bone growth in children and adolescents. GH stimulates these growth plates during sleep, leading to increased bone length and height.
- Mineralization: Sleep supports bone mineralization, in which calcium and other minerals are deposited in the bone tissue, making bones stronger and denser.
- Protein synthesis: During sleep, the body increases protein synthesis, essential for muscle growth and repair. This is particularly important for toddlers, who engage in a lot of physical activity that stresses their muscles.
- Muscle repair: Any minor muscle damage caused by daily activities is repaired during sleep, leading to stronger and healthier muscles.
While the fundamental mechanisms of the circadian rhythm are similar across humans, individual circadian rhythms vary from one person to the next. This is even more true in toddlers. Therefore, paying attention to your child’s unique circadian rhythm can help support all of these amazing natural processes that happen during sleep. But also remember that if you’re struggling with sleep-wake cycles that are different from your own, it’s not because your kid is giving you a hard time. It’s because that’s what their rhythm is telling them what to do!
How to get a toddler to sleep: 7 ways to support your toddler’s circadian rhythm
Healthy sleep patterns and sleep habits are the cornerstone of a well-functioning circadian rhythm. For toddlers, this means having a consistent bedtime routine, a regular bedtime and wake-up time, along with sufficient sleep duration. Disruptions to their sleep can lead to mood swings, irritability, and reduced ability to focus and learn, which we as parents know all too well.
1. Give lots of opportunities to play outside
Exposure to natural light is one of the most effective ways to regulate a toddler’s circadian rhythm. Playing outside not only provides essential physical activity but also helps set their internal clock. Natural light in the morning and afternoon signals to their bodies when it’s time to be awake and active, while the absence of light in the evening helps prepare them for sleep. Just try to be careful about too much sun exposure. Here are some key sun safety tips to help.
2. Facilitate movement and exercise
Encouraging toddlers to engage in regular physical activity through active play is not only important for their physical health but also for maintaining a healthy circadian rhythm. Activities such as running, jumping, and playing games help expend energy, making it easier for them to fall asleep and stay asleep so they can get a good night’s sleep. Active play during the day promotes better sleep quality, which in turn supports their overall development. If your toddler has a lot of energy at bedtime, you can try some toddler yoga.
3. Reduce screen time
Limiting screen time, especially in the evening, is important for maintaining a healthy circadian rhythm. The blue light emitted by screens can interfere with the production of melatonin, the sleep hormone, making it harder for toddlers to fall asleep just as it does for adults. Here’s some helpful advice on how to do it if you’re stuck.
4. Create a sleep-friendly environment
Make your toddler’s room conducive to sleep by keeping it dark and quiet during bedtime. Use blackout curtains to block out any external light (but not too much that they won’t naturally notice the light in the morning) and consider a white noise machine to mask disruptive sounds. A cool, comfortable room temperature also promotes better sleep.
5. Establish a consistent routine
Having a consistent daily routine helps regulate your toddler’s internal clock. Set regular times for meals, naps, and bedtime, and stick to them even on weekends as best as possible. A predictable routine provides a sense of security and helps toddlers understand when it’s time to sleep and when it’s time to be awake and active.
Toddlers generally sleep from around 7 p.m. to 6 a.m. If you’re thinking to yourself, But my toddler goes to sleep so late at night, you’re not the only one! But you should be aiming for around 11 hours at night, uninterrupted.
6. Manage nap times appropriately
Naptimes play an important role in supporting a toddler’s circadian rhythm, especially for those who still really need that daytime rest. If your toddler isn’t napping, their circadian rhythm may become misaligned, affecting their nighttime sleep.
Of course, it’s easier said than done, but do your best to keep that naptime as long as possible. If your child is transitioning to no naps or shorter naps, it’s advisable to give them some quiet time to rest their body and mind during the day, in a dark, quiet room. This will signal them to rest, and help them sleep better at night.
What if it rains a lot where I live? Or what if we have extra daylight/nighttime hours?
Our hometown got 42 days of straight rain this winter, and that’s not unusual. In Canada, weather and daylight conditions vary significantly by region. In places like Vancouver, where rain is frequent, getting outside even on cloudy days is important as natural light helps regulate your toddler’s circadian rhythm.
Then you have regions in the North that experience prolonged periods of daylight in summer and extended darkness in winter. In these areas, use blackout curtains to create a consistent sleep environment during endless summer days and maintain a bright, engaging atmosphere during the long winter nights.
And, regardless of the region, stick to a consistent routine for meals, naps, and bedtime to support your toddler’s internal clock and encourage healthy sleep habits. Incorporate physical activity to help manage energy levels and adjust to seasonal changes. Consistent routines and a tailored sleep environment can help your toddler thrive despite Canada’s diverse daylight and weather patterns.
What about circadian rhythm and time-zone changes?
Traveling across time zones or even the much-dreaded daylight saving time can disrupt a toddler’s circadian rhythm, which can throw them off as much as it does us parents. This is because the body’s internal clock struggles to adjust to a new time zone, leading to misalignment between their biological sleep-wake cycle and the local time.
Here’s what you can do to try to help them through:
- Gradual adjustments: Start adjusting your toddler’s sleep schedule one to two weeks before you travel or before the daylight-saving change. Shift bedtimes and wake times by 15-30 minutes each day to align gradually with the new time zone or the new clock time.
- Manage light exposure:
- Eastward travel: Expose your child to morning light upon arrival to help advance their circadian rhythm. Morning light helps shift the internal clock earlier.
- Westward travel: Provide exposure to evening light to delay their internal clock. Keeping the room dark in the morning will also help.
- Daylight saving time: Align morning light with the new schedule to reinforce the change. For example, if the clocks go forward, get your child outside in the morning light to help them adjust.
- Adjust nap times: Align naps with the new time zone or the adjusted clock time as soon as possible. Avoid letting naps extend too late into the day, as this can interfere with bedtime.
- Maintain consistent routines: Keep meal times, nap times, and bedtime routines consistent with the new time zone or schedule, but also do some research depending on the time difference. A predictable routine helps stabilize your toddler’s internal clock and reinforces healthy sleep patterns.
Apparently, there is a whole science to circadian rhythm while traveling. Read more about it here. Keep in mind that because of these disruptions to their circadian rhythm, your child’s physical activity may change as well. For instance, you may find they’re more jumpy than usual or more sluggish than normal. Typically, this is not a cause for concern, and after about a week or two (yes, it can take that long for toddlers, whereas adults may just a few days) your toddler will be back to their normal selves. (Until you travel back, of course!) So just be patient.
Recognizing circadian rhythm in your toddler’s physical development
Circadian rhythm is a natural cycle that we all have, but it’s slightly different for each person, especially toddlers who are still navigating their world. It may not seem like the most important thing in your child’s development, but working with biology—and not against it—can help improve your child’s sleep and overall physical health.
Though it’s not always as clear as night and day (toddlers are interesting creatures, after all), understanding how their unique circadian rhythm plays a role in their physical development can go a long way. The best we can do as parents is to help them regulate it better by following the tips here!
