Circadian What?

Some kids seem to be natural sleepers, easily taking lengthy naps each day, while others need a bit more assistance to get in the daytime sleep that they need. However, all children can take good, restorative naps if given the opportunity. The key to helping babies achieve their best nap is having them nap at the correct time of day. When sleep occurs is more important than the duration of the nap.

The Sciencey Stuff
We all have biological clocks called circadian rhythms, which are controlled by the rotation of the earth on its axis. These clocks create an internal timing mechanism for sleep based on dark (night)/light (day) cues. Sleeping in sync with these rhythms provides the best quality and most restorative sleep your body can achieve. It is also easiest to fall asleep and stay asleep at these times. Therefore it is important to be aware of your child’s circadian rhythms and schedule their naps accordingly, as this is the best way to ensure they get the sleep they need. A one-hour nap at the correct biological time is actually more restful than a two-hour nap outside of this window. The timing of these “sleep waves” changes as we age, but they are a constant for all children of the same age, varying only slightly from person to person.

Want to Relate?
An easy way for adults to relate to the power of these rhythms is to think about something like jet lag. While traveling outside of your time zone, most of us have a hard time falling asleep and staying asleep, and even if you do manage to get your usual amount of sleep, you still wake not feeling as rested. That is what it is like for a baby who is not napping in sync with their circadian rhythms.

So When Do These “Magical Sleep Waves” Occur?

• For babies four months and older who are taking two to three naps a day: the first nap should start between 8:30-9 a.m. The second nap should start between 12-1 p.m.
• For toddlers who are taking one nap a day: this nap should start between 12:30-1 p.m.
• Bedtime is also impacted by these rhythms. The best practice is to allow our children to fall asleep in sync with melatonin onset and in a rested state. This translates into a bedtime for babies and toddlers within the range of 5-8 p.m.

Remember that these are the times that you want your child to be asleep, so be sure to allot extra time for them to fall asleep. For example, if it takes your baby 15 minutes to fall asleep, you want to make sure that she is in her crib 15 minutes prior to the time you want her asleep.

Please note: Babies under four months do not yet have circadian rhythms, as they are just starting to develop at about that age. For these younger babies, be sure to watch the clock to keep their awake periods short, while also watching them for their sleepy signs. The key with these little ones is getting them to sleep before they become overtired.

Amy Lage is a graduate of the University of Massachusetts, Amherst and a Family Sleep Institute certified Pediatric Sleep Consultant. She is founder of Well Rested Baby. She offers a host of services including in person, phone, email and Skype/FaceTime consultations that can be tailored to meet any family’s needs and schedule. Please email her at amy@wellrestedbaby.com with any questions. Be sure to follow WRB on Facebook and Twitter too for more great sleep tips!