Sleep is not just a good experience, but a physiological restorative process of considerable importance. It is now well known that children are sleeping less than they used to in earlier periods. This is due to the conflicting demands of academic pursuits, both at home and in school, sports, time spent with friends and on the Internet, as well as other co-curricular activities.
How much sleep is optimal? It varies from person to person, but may be defined as the amount of daily sleep which keeps one fully awake and able to perform normally during the day. Others think of it as the amount of sleep that is needed to wake up refreshed in the morning.
In addition to sleep duration, it is also important to ensure a good quality of sleep, the right timing (day vs. night), consistency of sleep patterns and continuous sleep.
Negative effects of sleep deprivation
Adequate sleep during childhood is essential to health, memory, cognition, learning, and emotional stability. Less sleep during the first three years of life is associated with impulsive and hyperactive behavior and reduced cognitive development.
There is considerable variation between individuals and geographic regions, however. Asian children are found to sleep 1-2 hours less than European peers, on average,and about 40-60 minutes less than children in the US.
Some of the negative effects of too little sleep include:
- Impaired concentration
- Poor academic achievement
- Suicidal ideas
- Poor cognitive outcomes
- Long-term risk of obesity, depression, and hypertension
Evolution of sleep patterns
Newborn sleep is characterized by irregularity of body rhythms, and long sleep-wake cycles, with a total duration of up to 18 hours sleep both by day and by night. Daytime naps become shorter with growth, while night-time sleep becomes continuous. Even at adolescence, children usually require about 10 hours of sleep at night.
How do you know a child is sleepy?
Children often don’t tell you they are sleepy, so the following signs should warn you:
- Newborns: staring, puppet-like movements, frowning or yawning, and fussiness
- Older babies: crankiness, tearfulness, more or less activity, loss of interest in play, rubbing the eyes
- Toddlers: show signs of clumsiness, slowness, fussiness including tears and tantrums
Guidelines as to sleep duration at various ages
The guidelines as to how much sleep is required vary from expert to expert, a few of which are presented below:
National Heart, Lung and Blood Institute:
- Newborns: 16 to 18 hours a day
- Preschoolers required 11 to 12 hours a day
- School-aged children should sleep at least 10 hours a day
The US National Sleep Foundation (NSF) guidelines (from Carskadon et al):
- Newborns should sleep 12 to 18 hours
- Infants 3-11 months sleep 14-15 hours
- Between 1 and 3 years, children sleep 12-14 hours
- Preschoolers sleep 11-13 hours
- Children between 5-10 years sleep 10-11 hours
- Newborns sleep at least 15 hours, with most of it being at night, and the rest in one or two naps of up to 2 hours.
- Preschoolers sleep slightly less, and gradually give up napping by the time they start school.
- School-age children (5-13 years) need at least 10 hours of sleep a day.
National Sleep Foundation guidelines:
- Newborns (up to 3 months) should sleep 14 to 17 hours (range: 11-19 hours)
- From 4 to 11 months, they sleep 16-18 hours (range: 10-14 hours)
- Children 1-2 years sleep 11-14 hours (range: 9-16 hours)
- Preschool children between 3-5 years sleep 10-13 hours (range: 8-14 hours)
- School-age children between 6 and 13 years sleep about 9-11 years (range: 7-12 hours)
It is important that individuals in each group are able to get approximately the right amount of sleep. A chronic sleep deficit, either voluntary or forced, causes a sleep debt. This refers to the total number of hours of sleep that one loses.
A nap is a brief daytime sleep which is meant to substitute for lost night sleep. Though it does feel refreshing, it cannot produce all the benefits of night-time sleep. In addition, weekday nappers are more likely to nap on weekends as well, to have attention deficits, and to sleep less at night. On the other hand, less sleep at night reduces performance on standardized tests of vocabulary, auditory attention span, and other parameters.
Napping in very young children is possibly due to an increased need for sleep mounting up during the daytime hours. The duration of napping decreases continuously from about 7 hours as newborns to 45 minutes at age 4, and then ceases altogether. Preschoolers may find it difficult to remain awake for a full day of activity, however, and restricting naps may have a negative role on their mental processing.
If children in this age group do not require naps, they may be advanced in their cognitive development. It is therefore important to explore the reasons why children in this group do not nap. They may include cultural mores, parental pressures, biological maturation, or temperamental factors.
Sleeping late on weekends and days off
While sleeping late whenever you can does feel good, it can upset your body sleep-wake rhythms if it exceeds a couple of hours.
Ensure enough sleep
Negative cognitive outcomes are found to occur as a result of restricted sleep, but fortunately, the provision of better sleep durations reverses these findings.
It has been recommended that school start times be delayed especially from adolescence onwards, to make sure that the demands on the child’s time do not cut into the sleep period.
In addition, children should be told how important sleep is in their normal functioning, and encouraged to build up a healthy bedtime routine.