What Sleep Experts Are Telling Us about the Circadian Rhythm
Asking sleep experts for advice on how to put children to bed often feels like an exercise in futility. The standard tips are banal and predictable: avoid caffeine; remove the TV from their bedroom; don’t sleep on a full stomach; put up dark blinds. You have the feeling the experts are holding out on us – there has to be something more. And there is. Here’s the stuff they’d love to tell you, if they weren’t afraid of overwhelming you with science.
Ever wonder why most people sleep better when their bedrooms are cool? It’s because the circadian rhythm system that helps regulate sleep cycles is not just light sensitive, it’s temperature sensitive. Anything above a neutral air temperature both slows the body’s initiation of sleep and changes sleep patterns – a hotter room means an increase in non-REM sleep.
Experts share with us all kinds of interesting things about circadian rhythm
77 percent of children use television as part of their pre-bedtime routine. Sitting still and vegging out for half an hour should, theoretically, help a child unwind, as long as they’re not watching a show that excites them too much. However, the brightness of the screen undermines the theory. The light from a television or computer can delay both the necessary drop in core body temperature and melatonin production – and thus delaying sleep onset – by two hours.
• We’re all familiar with the agony of being super exhausted, yet not being able to fall asleep for hours. What gives? It’s because after just a few days of shortened sleep, the brain starts making extra stress hormone cortisol. It takes six times as long for this stress hormone to drop to a low-enough level that sleep is possible.
• In one study of 170 children, those in white collar families tended to be in bed later and get up earlier than those in working class families. Yet they actually got more actual sleep. How is that possible? It’s because their bedtimes and wake-times were more consistent; they stuck to their routine. This made their sleep more efficient – they rolled around in bed far less.
• Inconsistent bedtimes are, for all practical purposes, homemade jet lag – the desynchronization of the two systems that regulate sleep, the circadian rhythm and the homeostatic pressure system. Staying up three hours later on weekends is equivalent to flying across three time zones every weekend.
• With children averaging three hours of television per day, it’s hard to make the case children are universally overscheduled. But the most driven children are the most overscheduled – and the most sleep deprived. In some ways, these busy overachievers are those who concern the experts the most. According to University of Minnesota’s Dr. Kyla Wahlstrom, a motivated student can sacrifice sleep to maintain high GPAs, but she may pay for that success with higher levels of depression and stress. Teen boys who have a high number of extracurriculars are significantly more likely to be involved in a fall-asleep car crash. And those with part-time jobs both sleep less and have lower grades.
• For the majority of kids, rather than thinking it’s a choice between sleep and activities, the opposite is true: students who sleep more are involved in more afterschool activities – with no detriment to their grades. They have the energy to be involved. Schools that have delayed start times have seen their students sleep more and increase their participation in sports and extra-curricular activities.
• Naps are not quite the salve we imagine. They appease the homeostatic pressure system, but not the circadian. You wake up feeling better – a two hour nap is equivalent to 150 mg of caffeine – but naps do nothing to repair diminished cognitive functioning. The intellect is just as dulled after the nap as before. Kindergartners who take long naps, for instance, do worse on puzzle-solving.
• 16 percent of kids snore a few times as week. As recently as 2002, the American Academy of Pediatrics opined that children’s snoring was a benign condition not warranting treatment. Just five years later, researchers now caution that kids’ snoring is not like adult snoring at all – even a little snoring is a major cause for concern, because their developing brains can be deprived of oxygen.
• Common sleep disorders such as nightmares, restless leg syndrome, and frequent night waking can have a startlingly negative impact on children’s development – from using drugs at 14 to having clinical-level anxiety as adults. Research by University of Michigan’s Dr. Ronald Chervin indicates as many as 25% of kids diagnosed with ADHD have an underlying sleep disorder causing their symptoms. If treated for their sleep disorder, the ADHD would magically disappear. Despite the risks posed by sleep disturbance, the number of children treated for them is “vanishingly small.” Parents should consult a qualified sleep specialist – few pediatricians have expertise with sleep problems. Waiting to see if a child grows out of a sleep problem isn’t the answer.