You start sleeping less in early adulthood, with sleep duration declining from your 20s until around age 33, then staying relatively stable until your 50s when it might slightly increase again; however, sleep changes throughout life, with infants needing the most and teenagers needing 8-10 hours, while adults generally need 7+ hours.
The koala is famous for sleeping around 20-22 hours a day, which is about 90% of the day, due to their low-energy diet of eucalyptus leaves that requires extensive digestion. Other extremely sleepy animals include the sloth (up to 20 hours) and the brown bat (around 20 hours), with some snakes like the ball python also sleeping up to 23 hours daily.
The 3-2-1 bedtime method is a simple sleep hygiene strategy: stop eating 3 hours before bed, stop working 2 hours before bed, and stop using screens (phones, tablets, TVs) 1 hour before sleep, helping your body transition to rest by reducing stimulants and digestive load for better sleep quality. A more detailed version adds 10 hours (no caffeine) and 0 (no snoozing) for a 10-3-2-1-0 rule.
Key Findings on Sleep Duration
They found that the youngest participants in the sample (minimum age 19) slept the most, and sleep duration declined throughout people's 20s and early 30s before plateauing until their early 50s and increasing again.
Gen Z stays up late due to a combination of technology (blue light, endless content), significant stress and anxiety (FOMO, financial/global worries), biological shifts (natural teenage circadian rhythm), and "revenge bedtime procrastination," where they sacrifice sleep for personal time, often in bed, scrolling social media. This digital-heavy, high-stress lifestyle creates overstimulation and a misalignment with natural sleep patterns, leading to chronic sleep deprivation, notes the American Academy of Sleep Medicine and the Sleep Health Foundation.
Whilst boomers and millennials may use the 😂 emoji, this has long since been deemed 'uncool' (or 'cheugy') by Gen Z. Instead, this has been replaced by the skull (💀) or the crying emoji (😭), dramatising the idea of 'dying with laughter'.
Across much of the world, it is no longer middle-aged adults who are the most miserable. Instead, young people, especially Gen Z, are reporting the highest levels of unhappiness of any age group.
Best survival rates were found among those who slept seven hours a night. A group sleeping eight hours was 12% more likely to die within the six year period than those sleeping seven hours, other factors being equal. Even those with as little as five hours lived longer than those with eight hours or more nightly.
The 5-3-3 rule is a baby sleep training method for night weaning and fostering independent sleep, involving a baby sleeping 5 hours, staying awake for 3 (for a feed if needed), then sleeping another 3 hours, and continuing in 3-hour increments, teaching them to self-soothe after the initial long stretch, though it's a flexible guideline, not strict; it aims to create longer stretches for parents while meeting the baby's needs, often used around 4-6 months.
Prevalence of Sleep Disturbance and Daytime Tiredness
For SLEEPDIST, the highest prevalence of complaints was in the youngest group (18-24 yr) and the lowest prevalence of complaints in the oldest groups (older than 80 yr for women and 70-74 yr in men).
Depending on one's age and individual needs, the National Sleep Foundation (USA) states that adults need seven to nine hours of good quality sleep per night to remain healthy and alert. School-age children require between nine and eleven hours, while older adults may need only seven to eight.
Signs of poor core sleep (deep, restorative sleep) include waking up foggy, daytime fatigue/energy crashes, poor concentration, irritability, frequent illness, memory issues, and mood swings, indicating your brain and body aren't fully repairing and consolidating memories. You might also experience increased sugar cravings, slow muscle recovery, and a weakened immune system.
In his piece, he revealed that through his years of research, he's found that rumination is the biggest thing that causes poor sleep. He says that being worried about something at night has affected his own ability to fall asleep.
Among the most rested countries surveyed by Sleep Cycle, an app that tracks how much shuteye people are getting, New Zealand comes top with the average Kiwi clocking up in excess of 7.5 hours per night. Finland, the Netherlands, Australia, the UK and Belgium all rank highly for sleep, too, with Ireland close behind.
Yes, the Navy SEAL sleep trick (an 8-minute power nap with elevated legs) is a real technique for quick rest, popularized by former SEAL Jocko Willink, that helps improve alertness and reduce fatigue, though its effectiveness depends on individual relaxation skills and it's not a substitute for full nighttime sleep. The method involves lying down, elevating your feet above your heart (on a chair or couch), relaxing facial muscles, dropping shoulders, and clearing your mind for about 8-10 minutes to promote relaxation and blood flow, preventing grogginess.
SIDS is less common after 8 months of age, but parents and caregivers should continue to follow safe sleep practices to reduce the risk of SIDS and other sleep-related causes of infant death until baby's first birthday. More than 90% of all SIDS deaths occur before 6 months of age.
Stick to a sleep schedule
The recommended amount of sleep for a healthy adult is at least seven hours. Most people don't need more than eight hours in bed to be well rested. Go to bed and get up at the same time every day, including weekends. Being consistent reinforces your body's sleep-wake cycle.
The "3-2-1 Bedroom Method" (or a variation like the 10-3-2-1 rule) is a sleep hygiene strategy to improve rest by staggering when you stop certain activities before bed: stop heavy food/alcohol 3 hours before, stop work/mental stress 2 hours before, and turn off screens (phones, TVs, computers) 1 hour before sleep, creating a better wind-down for your body.
Key takeaways: A lack of sleep is a top cause of premature aging. Most adults over age 18 need 7 to 9 hours of sleep per night. Getting enough sleep improves concentration and gives your body time to repair and recharge.
For most people, short naps don't tend to affect sleep quality overnight. But if you have trouble falling asleep or staying asleep at night, napping might make these problems worse. Long or frequent naps might interfere with nighttime sleep.
Koalas are the longest sleeping-mammals, about 20–22 hours a day.
A Breed in Decay: Why U.S. Millennials and Gen Z Are Dying at an Alarming Rate — Faster Than Any Other Generation in Recent History.
There are a lot of different reasons why you might feel like nothing makes you happy. Certain mental health conditions like depression, anxiety, and PTSD can cause severe feelings of unhappiness, lack of motivation, and disinterest in activities that used to bring joy.
Bae – Boyfriend or girlfriend.