Keep those smartphones out of their rooms at night. Picture: Supplied

When one of my four childrne is snappish, I almost immediately think about how much sleep the child had gotten the night before. If less than usual, then I generally know the why behind the crankiness-and brace myself for the onslaught of whininess. 

"Sleep supports healthy growth and development," says Terry Cralle, a nurse and certified clinical sleep educator. "Children who sleep less than the recommended number of hours suffer an increase in behavior, learning and attention disorders."

But in today's fast-paced world, sleep is often overlooked or sacrificed. "Studies show that many children are getting less sleep than they did 20 years ago," says Cralle.

Parents also underestimate the amount of sleep a tween or teen needs. Last year, the American Academy of Sleep Medicine, backed by the American Academy of Pediatrics, changed its recommendations for how much sleep children should get:

- Children 6 to 12 years: 9 to 12 hours of sleep each 24-hour period.

- Teens 13 to 18 years: 8 to 10 hours of sleep each 24-hour period.

The factors contributing to kids not getting enough sleep vary, but here are some of the top contenders:

Smartphones

"Yes, a smartphone makes a good alarm, but not if kids are texting or checking social media all night," says Elisabeth Stitt with Joyful Parenting Coaching. Christine Stevens, a certified sleep consultant with Sleepy Tots Consulting, adds that the "blue wavelength of light emitted by these devices tricks the brain into thinking it's time to wake up and inhibits the production of melatonin, a key sleep hormone. So keep those smartphones out of their rooms at night. You can have them charge in your room to keep an eye on them, or another docking station.

Varying bedtimes

An occasional late night is okay, but consistency is the key to good sleep habits. A consistent bedtime helps set circadian rhythms and provides a sense of order and structure, Cralle says. 

Most nights, our own 8-year-old goes to bed at 8pm, our 10-year-old at 8:30pm, our 12-year-old at 9 p.m., and our 14-year-old at 9:30pm. The more consistent bedtimes are, Cralle says, the healthier the sleep habits.

Television

Like phones, children should really not have televisions in their rooms. They will be tempted to watch a show later than their body wants to be awake, and the blue light from TV is similar to that in phones. "Children with TVs in their bedroom sleep on average an hour less than other children," says Dr. Robert S Rosenberg, board certified Sleep Medicine Physician and author of The Doctor's Guide to Sleep Solutions for Stress & Anxiety.

Too many activities

Sleep is another reason to just tone down all those activities. Packing a kid's schedule means there is less time to unwind or relax before bedtime, and sleep should be a priority.

"Catching up" on the weekends

Catching up on sleep doesn't really work. If a child gets to bed too late all week, and you think it'll work itself out during the weekend, think again. "Letting teens go to bed in the wee hours of the morning, then sleep till the afternoon on weekends reinforces and worsens the circadian shift (toward later bedtimes around age 13), making it almost impossible to return to a normal sleep/wake schedule on school days," Rosenberg says.

Caffeine intake

Caffeine is a stimulant that increases wakefulness. But even if a child drinks something with caffeine in it hours before bedtime, it can still impact their sleep. "A lot of tweens and teens rely on energy drinks to keep them alert and awake in school," Rosenberg says. "But these shots of caffeine can make it more difficult to fall asleep at night."

Other tips include:

  • Get regular exercise. I've noticed that my kids often have the most trouble falling asleep on rainy days when they've been cooped up inside. "Exercise promotes better moods, decreases anxiety and promotes sleep," Rosenberg says.
  • Talk about the importance of sleep. "Educate your children on why we need sleep and highlight what happens when we don't get enough of it," Stevens says. For example, explain to them how sleep helps with memory, mood and athletic performance.
  • Incorporate downtime. "Parents grossly underestimate the amount of downtime kids need after they have been focused at school all day," says Stitt. She recommends parents help kids create at least a half hour soothing, winddown routine that doesn't include electronics before lights out.