Oct 30, 2025
3 min read
How much sleep do you really need?Scientists have emphasized a "U-shaped risk".
Most adults do not need eight hours of sleep;A growing body of evidence and evolutionary studies show that many healthy adults sleep closer to seven hours a night, with health risks on both sides of it in a U-shaped pattern.
According to Harvard evolutionary biologist Daniel E. Dieumer E. Dieumer E. Rigid E. Dieerman, people without electricity in the primitive age went six to seven hours without sleep.Lieberman based his research on exercise research for his book, Physical Activity, Rest Science and Health, with interviews with the CEO's diary.
What a free debate
- Lieberman says the idea that humans have a "natural" eight hours of sleep is unfounded. Local data from communities without electric lighting indicates that a typical night's sleep is about 6 to 7 hours, contradicting the cultural prescription of 8 hours as a goal.
- Sees the modern eight-hour dogma as a legacy of the Industrial Revolution rather than a biological necessity, and points to epidemiological curves where risk bottoms out at about seven hours, creating a U-shape with higher risk for both short and long sleepers.
- The wide-ranging honors of his position are often superior to more than eight for health outcomes, highlighting the variability by age and condition, and insomnia is not the best match.
How much sleep do you really need?
- In the notes, sleep scientist Rebecca Robbins tackles the eight-hour belief, explaining how the score came about and offering practical ways to improve sleep quality instead of fixing a single number.
- More than a third of Americans get at least seven hours of sleep, which emphasizes the importance of consistency and sleep hygiene rather than chasing the magic number.
- The American Academy of Sleep Medicine and Society for Sleep Research recommends "seven or more hours a night" for adults. Apparently it started at seven instead of eight.
- Mayo Cligic Guide Guide: Adults who need seven hours or more, and many changes in the year are not good, and pregnant, and the violence of sleep but do not increase the body.
U-shaped risk curve
- Large collections indicate the duration of sleep and the main effect, as the Nadir is around seven hours for body temperature and the risk of cardiac death and the risk of death.
- UK VISBANK analysis, showing permanent relationships from there (after adjusting for less than every two hours, long sleep duration, long sleep duration and life expectancy).
- Mechanical work and biomarkers with variations of less than seven or more than eight to nine hours are associated with markers of biological aging, although prolonged rest may confound cause and effect.
Practical Sleep Guidelines
- Aim for seven to nine hours, use at least seven if you wake up refreshed and work well;Turn to glory in the old days, strength training, strength training or pregnancy, regret it if necessary.
- Pay attention to the U shape: both chronic short sleep (less than seven hours) and moderately long sleep (more than nine hours) are associated with higher risk;If you need more than nine hours on a regular basis, consult a physician to assess any underlying conditions such as depression, sleep apnea, or chronic illness.
- Prioritize consistency and quality- regular bed and wake times, morning light, reduced evening blue light, dark, cool rooms, and limiting caffeine/alcohol- rather than obsessing over the eight hour goal.
"Sweet spot" for sleep
- The eight-hour rule is a simplification of culture, not a universal biological requirement.Seven hours of flexible "sweetness" based on life stage and health.
- Business leaders and individuals need to reframe sleep goals based on evidence-based scope and measurable daily functions, and invest in sleep quality practices that improve performance and long-term health without imposing a rigid eight-hour quota.
For this story, Generative AI was used to help with the initial draft.An editor verified the accuracy of the information before publication.
