People who sleep 4 hours a night are typically Natural Short Sleepers (NSS), a rare group (1-3% of the population) with a genetic mutation (like in the ADRB1 gene) allowing them to function well on 4-6 hours, feeling rested without stimulants, unlike most people who become sleep-deprived. This isn't a trained habit but a biological trait, with examples including figures like Margaret Thatcher, but most "short sleepers" (like CEOs claiming 4 hours) are actually chronically sleep-deprived.
What are short sleeper syndrome symptoms? The main symptom of short sleeper syndrome is sleeping between four and six hours each night. You wake up even if you don't have to get up for work, school or other obligations.
Napoleon Bonaparte, one of the greatest military leaders of all time. He is also one of the most famous nappers. Napoleon had a notoriously harsh schedule, only sleeping about four hours a night. He compensated by frequent naps which would inspire his genius strategic movements.
Bottom line: Four hours of sleep can be tolerated occasionally but is not sufficient as a regular pattern for the vast majority of adults. Aim for 7--9 hours and use naps and sleep‐optimization strategies if constraints arise.
Nooyi revealed her habit of sleeping only 3-5 hours a night. Waking up early and going to sleep after work is done is not everyone's thing, but I found it relatable. Also, she was diligent in her educational endeavors.
Musk wakes up around 9 a.m. and says he starts every morning with steak and eggs. Musk told The Wall Street Journal in 2023 that he usually goes to bed around 3 a.m. and sleeps for six hours. So, he's typically waking up around 9 a.m. each day.
ELI5: Gordon Ramsay said he sleeps 3 hours a day.
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.
As predicted, those with only 4 or 6 hour of sleep had lower scores on all testing, including lapses of attention, reduced cognitive thought, slowed working memory, depressed mood, and delayed reaction times [15].
How to get through the day after a bad night's sleep
Tom Cruise
Tom Cruise reportedly sleeps in a soundproof "snoratorium" due to his loud snoring. This habit began during his marriage to Katie Holmes. Despite his busy lifestyle, the actor has shared that he typically gets only four to six hours of sleep each night.
Some evidence suggests that high IQ is associated with later sleep patterns. However, it is unclear whether the relationship between IQ and later sleep is due to biological or social effects, such as the timing of working hours.
Which jobs have the highest rates of sleep deprivation? Transportation workers (especially truck drivers), healthcare workers, manufacturing employees working night shifts, and business executives have the highest rates of occupational sleep deprivation.
But in recent years, scientists have discovered a rare breed who consistently get little shut-eye and are no worse for wear. Natural short sleepers, as they are called, are genetically wired to need only four to six hours of sleep a night.
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.
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.
For adults, getting less than seven hours of sleep a night on a regular basis has been linked with poor health, including weight gain, having a body mass index of 30 or higher, diabetes, high blood pressure, heart disease, stroke, and depression.
Einstein slept nearly 10 hours a day. He was known to be a firm believer in the importance of a good night's sleep, often aiming for around 10 hours of rest. However, his approach to sleep was somewhat unconventional.
The 3-2-1 sleep rule is a simple wind-down routine: stop eating and drinking alcohol 3 hours before bed, stop working/mentally stimulating activities 2 hours before, and turn off screens (phones, TVs) 1 hour before sleep, helping you transition to rest by reducing stimulants and preparing your mind and body. It's often part of a larger 10-3-2-1-0 rule, which also adds no caffeine 10 hours prior and no hitting snooze (0) in the morning.
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.
Arnold Schwarzenegger famously advocates for getting only six hours of sleep a night, claiming he consistently slept that amount while achieving immense success in bodybuilding, acting, and politics, famously telling critics they just need to "sleep faster" to fit more into their 24-hour day. While younger, he needed more sleep (around nine hours), but as he aged and his intense training lessened, six hours became sufficient, allowing him more time for his goals.
Gordon Ramsay was diagnosed with basal cell carcinoma (BCC), a common and treatable form of skin cancer, which required surgical removal from his jawline near his ear in late August 2025, leading him to share his experience online to urge fans to use sunscreen and protect their skin. He posted photos of his bandages, emphasizing sun safety and thanking his medical team.
Everyone sleeps differently. For example, some billionaire entrepreneur philanthropists like Richard Branson and Bill Gates begin and end the day with a heavy and light workout, respectively. They require over 7 hours of uninterrupted shut-eye before beginning the day anew.