Ever wonder why babies don’t readily sleep through the night or why toddlers seem to become afraid of monsters under the bed? How about why teens always seem to oversleep their alarms or why grandpa takes so many naps? Or perhaps even why your own slumber fluctuates as over time?
Find out the answer to these questions, and learn more about how sleep changes through the years based on science and views from sleep experts.
Sleep Needs Vary Significantly By Age
Newborn, infants and toddlers require more sleep, and have more erratic sleep pattern than older children. Teenagers need more sleep than adults as their bodies go through a period of tremendous change. We get our best sleep in early adulthood, before the quality and quantity tapers off as we age.
The National Sleep Foundation has consulted with scientists in various fields to update the recommended sleep durations. Most sleeping still takes place during night when melatonin production is higher. But, babies and younger children nap during the day as well to accumulate sleeping hours in a 24-hour period.
The ranges are large enough to accommodate most of the population. Of course, some outliers get by fine on more or less than the recommended amount. This is a rarity linked to gene variants or illness, however. The vast majority should be sleeping within the recommended guidelines on a regular basis to avoid the negative effects of sleep deprivation.
Circadian rhythms, the sleep-wake cycles regulated by dark and light, take about 6 weeks to develop and 3-6 month to standardize. Between sleep, babies are often active. But, they require 14 – 17 hours of sleep per 24 hour in their first three months.
Newborns express their need to sleep by fussing, crying, rubbing their eyes or exhibiting similar actions. They may experience separation anxiety, which can disrupt sleep. Their sleep cycle is intertwined with other basic needs: feeding, diaper changing, and nurturing (which often disrupts parents’ sleep).
Sleep need decreases to between 12 and 15 hours when they are 4 to 11 months. By 9 months, 70-80% of infants will sleep through the night. Usually, infants take one to four naps per day that last between 30 minutes and 2 hours. If you put them to bed when they are drowsy, rather than asleep, they will more easily develop sleep independence instead of signaling their parents.
Establishing a routine and having a friendly sleep environment will help babies between the ages of 4 and 11 months fall asleep independently. Exposing them to light and noise during the day, and quieting down towards the night helps them adjust to more regular sleeping hours. At night, place them on their back, clear of blankets or other soft objects.
Adequate rest proves very important for babies, as plenty is going on in the brain and body during these crucial months. Babies spend about half of their sleep time in Rapid Eye Movement (REM) sleep and the other half in non-REM sleep in cycles of 50 minutes.
REM sleep is when our brains are active and dreaming occurs. Breathing and heart rate can become irregular and our bodies, immobile. During non-REM sleep blood supply to muscles increases, energy is restored, tissue growth and repair occurs, and important hormones are released for growth and development.
Toddlers between the ages of 1 and 2 years experience a time of increased motor, cognitive and social abilities. They are establishing imagination and independence, which affects their sleep habits.
With independence comes a pushback on going to sleep. The best approach is to communicate consistent limits about bedtime and naptime. Toddlers need between 11 and 14 hours of sleep.
The development of imagination may contribute to nightmares and nighttime fears, which explains the monsters under the bed. A security object, such as a blanket, can make your toddler less afraid.
Preschoolers and School Aged Children
By the time children hit the preschool age, between 3 and 5 years, their REM sleep has decreased to about 30% of the night. Parents often phase naps out of the routine for school, with most children after 5 forgoing sleep in the daytime.
Preschoolers face many of the same issues as toddlers. School-aged children also face increasing demands on their time between homework, television, sports, and computers.
If children have poor sleeping habits, they may demonstrate behavior problems such as mood swings or an inability to focus and learn at school.
With sleep deprivation, adults get sleepy, while kids often act the opposite. They tend to overcompensate for their tiredness by exhibiting signs of hyperactivity, inattentiveness, and impulsive behavior, with may be misdiagnosed as ADHD. According to experts, children who did not have a regular bedtime exhibited ADHD-like behaviors 8 times more frequently than children who had a regular bedtime.
Wondering why your teen resists going to bed at night, and is so difficult to wake them in the morning? Part of it is because their circadian rhythm shifts approximately one hour later during this time. This shift brings a tendency to sleep and wake later.
Although teens need between 8 and 10 hours of sleep, most aren’t getting enough. Sleep patterns may be irregular between weekdays and weekends, when they stay up later and sleep in without having to wake up for school.
The good news is that most of the sleep that teens and younger adults experience is slow wave sleep, which is the most restorative. However if teens aren’t getting enough sleep at night it can make it harder to pay attention in school, lead to poor eating habits, contribute to inappropriate or aggressive behaviors, worsen acne, or even aggravate feelings of depression, stress and anxiety.
Avoiding electronics one hour before bedtime can help teens get to sleep earlier. The blue-wave light emitted by phones, tablets and TVs is disruptive to melatonin production.
Sleeping as an Adult
>The most satisfying and restorative sleep takes place when you are a young adult. In your early twenties, you get most Stage III sleep, which is the deepest and most restorative. After your early 20s you spend more of the night in Stage II sleep, or middle sleep, which is mildly restorative.
As you get older, your sleep becomes less satisfying and less restorative. And, the modern pace of life means adults are sleeping less than ever before. More than 40% of the adult population snooze less than the recommended amount of sleep per night, compared to 11% in 1942.
Sleep often mirrors your general health, rather than your age. The better your health the better you sleep, and vice versa.
Women also experience unique disruptions in sleep throughout their adult lives. Events like pregnancy, motherhood, and menopause all play a role in the quality of rest.
Aging & Seniors
The circadian clock moves back in seniors. As such, many prefer to wake earlier in the morning and sleep earlier at night. Changes in sleep patterns are a normal part of aging.
Health issues and aging can hinder older adults’ sleep patterns. Sore backs, hips, and knees keep people awake, as might other physical or psychiatric illnesses or the medications treating them.
Seniors may have a harder time falling asleep. They also wake frequently during the night, fragmenting sleep and deregulating the circadian clock. With age, the body spends more time in the lighter stages of sleep, meaning more total rest time is needed to fully recharge. So, it’s no wonder seniors like to nap in the day!
As they unlearn the rhythms of sleep they have been using their whole life, sleep patterns revert back to the sleep schedules of children. Light therapy and exercise can help, as will healthy habits. As responsibilities decrease after retirement, there is no reason why seniors can’t enjoy a good daytime snooze though.
Aiming to make a healthy amount of rest part of your daily routine, practicing good sleep hygiene, and emphasizing its importance as a family can help develop lifelong habits.