Sleep and Longevity: Why Consistency Matters as Much as Hours

Updated September 2026

Sleep isn't downtime. It's when your body and brain do essential maintenance: consolidating memories, regulating hormones, supporting immune function and clearing waste from the brain. Sleep also tends to become lighter and more broken as we age, which makes good habits even more important.

How much sleep do adults need?

The Sleep Health Foundation recommends 7 to 9 hours a night for most adults.¹ Regularly getting less is linked in research with poorer health outcomes, and very long sleep can also be a sign that something else needs attention.

Why regularity matters

One of the more interesting findings of recent years is that when you sleep may matter as much as how long. In a UK Biobank study of around 60,000 adults who wore activity trackers, people with the most regular sleep patterns had a lower risk of death over the following years than those with the least regular patterns, and sleep regularity was a stronger predictor of mortality than sleep duration.²

A 2024 study published in Nature Medicine followed nearly 7,000 people wearing consumer devices for an average of 4.5 years and found that sleep duration, sleep stages and irregular sleep were associated with the risk of developing a range of chronic diseases.³

Both are observational studies, so they show associations rather than proving cause. But they support a simple message: a consistent bed and wake time is worth prioritising.

Healthy sleep habits and lifespan

Research presented at the American College of Cardiology in 2023, based on data from more than 172,000 US adults, found that people who had all five healthy sleep factors (enough sleep, rarely having trouble falling or staying asleep, feeling well rested most days and not using sleep medication) had a longer estimated life expectancy than those with none or one.⁴

Habits that help

• Keep a consistent schedule. Aim to go to bed and get up at similar times every day, including weekends.
• Get morning daylight. Light soon after waking helps set your body clock.
• Keep your bedroom cool, dark and quiet. Many people sleep best at around 18 degrees Celsius. Blackout curtains or an eye mask can help.
• Wind down before bed. Dim the lights and put screens away where you can for the last hour of the evening.
• Watch caffeine timing. Caffeine can affect sleep for hours, so keep it to the morning and early afternoon.
• Go easy on alcohol. It can make you drowsy, but it fragments sleep later in the night.
• Move during the day. Regular physical activity is linked with better sleep quality.

What about catching up on weekends?

A sleep in can help you feel better after a short night, but large differences between weekday and weekend sleep times shift your body clock, a bit like mild jet lag. Try to keep the difference to an hour or so.

When to see your GP

Speak to your doctor if you regularly struggle to fall or stay asleep, snore loudly or stop breathing during sleep, or feel very sleepy during the day despite enough time in bed. Conditions such as insomnia and sleep apnoea are common and treatable.

The bottom line

Aim for 7 to 9 hours, keep your bed and wake times consistent, and protect the hour before bed. These habits cost nothing and support almost every other part of your health.

Where Keeper fits: Supplements can't replace good sleep habits. Many people are interested in magnesium for sleep, and our magnesium guide covers what the research shows. Keeper Complete Longevity includes 250 mg of magnesium glycinate and 1,000 mg of glycine in each daily serve. Every batch is third party tested.

References

1. Sleep Health Foundation. Sleep Health Foundation Australia.
2. Windred DP et al. Sleep regularity is a stronger predictor of mortality risk than sleep duration. Sleep. 2024.
3. Zheng NS et al. Sleep patterns and risk of chronic disease as measured by long term monitoring with commercial wearable devices. Nat Med. 2024.
4. American College of Cardiology. Getting good sleep could add years to your life. 2023.

This article is general information only and isn't a substitute for advice from your healthcare professional.