Ask most people when they slept the least, and many will point to their college years or their twenties. A large international study suggests otherwise: across the world, people tend to sleep the least from their early thirties to their early fifties.
A video game turned sleep study
The research, led by Professor Hugo Spiers at University College London, used data from Sea Hero Quest, a mobile game created to help Alzheimer’s research by measuring players’ navigation skills. Players were also asked about their sleep. That produced an unusually large dataset: more than 730,000 people across 63 countries. The findings were published in Nature Communications.
Earlier sleep studies often focused on one age group, a specific sleep problem or a smaller number of people. The size and global reach of this dataset let researchers look at sleep across the whole adult lifespan.
Three phases of adult sleep
The researchers identified three distinct phases:
- Early adulthood (about 19 to 33): Sleep was longest at the start of adulthood, then steadily declined.
- Mid-adulthood (about 34 to 53): Sleep reached its lowest point and stayed there, leveling off.
- Late adulthood (about 54 and older): Sleep duration began to rise again.
The pattern was remarkably consistent for men and women, across countries and across education levels.
Why midlife sleep suffers
The researchers pointed to the demands of midlife, especially work and raising children, as likely reasons. As those responsibilities ease, often in the early fifties, sleep tends to increase. Other midlife changes, such as stress and, for many women, the hormonal shifts of perimenopause and menopause, can also disrupt sleep.
Other interesting findings
- The global average was about 7 hours a night.
- Women slept slightly longer, by about 7 to 8 minutes a night on average.
- Location mattered. People in Eastern European countries slept the most, around 20 to 40 minutes more per night, while people in Southeast Asian countries such as Indonesia, Malaysia and the Philippines slept the least.
- Culture and geography may explain differences. Attitudes toward napping, typical bedtimes and distance from the equator all appeared to play a role.
Because the data came from people’s own reports while playing a game, it may not be as precise as sleep measured in a lab. Still, the sheer scale makes the overall patterns compelling.
Why sleep matters
Most adults need at least 7 hours of sleep a night. Regularly getting less is linked to higher risks of heart disease, diabetes, weight gain, depression, weakened immunity and accidents. Sleep also supports memory and brain health, which is part of why researchers studying Alzheimer’s are interested in it.
Tips for better sleep in a busy stage of life
- Keep a consistent schedule, even on weekends.
- Protect your wind-down time. Dim the lights and put away screens 30 to 60 minutes before bed.
- Watch caffeine and alcohol, especially in the afternoon and evening.
- Make your bedroom sleep-friendly: cool, dark and quiet.
- Get daylight and exercise earlier in the day to support your body clock.
- Share the load. Parents can take turns with night-time duties when possible.
- Talk to a doctor about ongoing insomnia, loud snoring or daytime sleepiness, which can signal treatable sleep disorders.
The bottom line
A study of more than 730,000 people found that sleep is shortest from the early thirties to the early fifties, likely because of work and family demands. Prioritizing good sleep habits during these years can protect long-term health.
This article is for general information and isn’t medical advice. Talk with your healthcare provider about your individual needs.
