Biohack Your Sleep: Regularity Leads To Longer Lives Over Duration (2025)

How long do you need to sleep at night? The answer most commonly given is: “7-9 hours”. This isn’t an inherently bad answer; however, new research suggests that we might be asking the wrong question.

Instead of being concerned with sleep duration, an article published in Sport Sciences for Health suggests we should probably be focusing more on sleep regularity. This study found that following normal bedtime and waking hours can be a greater predictor of health and overall mortality compared to sleep duration.

If you want to biohack your sleep, you need to read this.

The Study: Sleep regularity is a stronger predictor of mortality risk than sleep duration: A prospective cohort study (2024)

A 2024 study published in Sport Sciences for Health analyzed data from 60,977 adults in the UK Biobank. 

These participants wore wrist accelerometers for one week between 2013 and 2016, which objectively tracked their sleep duration and sleep timing consistency. Collectively, this data is known as the Sleep Regularity Index (SRI).

Mortality outcomes were then tracked for roughly 6.3 years using national health records.

The researchers analyzed this data to compare the impact of sleeping patterns on mortality and overall health, specifically examining the effects of sleep regularity versus sleep duration.

Regularity vs. Duration: What Did Researchers Find?

• Sleep duration refers to the average number of hours you sleep per night (e.g., 6 hours vs. 8 hours).
• Sleep regularity measures how consistent your sleep and wake times are across days — for example, going to bed at 11 pm and waking at 7 am most nights.

Contrary to popular wisdom, the study found that day-to-day consistency in sleep patterns was a better predictor of long-term health and mortality than just sleeping “enough”. Researchers found that having a more consistent sleeping pattern resulted in; 

• All-cause mortality: 20%–48% lower risk 
• Cancer mortality: 16%–39% lower risk 
• Cardiometabolic mortality: 22%–57% lower risk

More interesting is that these numbers were more significant than the effect of getting adequate sleep.

In fact, some indicators, such as cancer mortality, saw no significant difference with variations in sleep duration. This means only sleep regularity was associated with a decrease in risk.

All in all, sleep regularity was a greater predictor of health and mortality.

In this study, those with sleep consistency in the top 20% had regular sleep times within a 1-hour window. For example;

• They went to bed from 9–10 pm or 10:30–11:30 pm 
• They woke up from 6–7 am or 7–8 am

On the contrary, those in the bottom 20% had sleep times within a 3-hour window. This means;

• They went to bed from 10 pm to 1 am or 11 pm to 2 am
• They woke up anytime from 5 am to 8 am or 8 am-11 am

Therefore, to optimize your sleep, researchers suggested that;

Now, this doesn’t mean duration has zero value – you can’t sleep from 1 am to 5 am every night and expect to perform optimally. It still seems that 6 hours of total sleep remains a good minimum goal.

Why Might This Happen? Our Circadian Rhythm 

You may not have heard of this before, but researchers actually have a pretty good theory as to why this occurs. It comes down to our circadian rhythm, a physiological function the general public vastly underestimates.

The circadian rhythm is your body’s internal 24-hour clock that regulates a ton of essential biological processes, including; 

• Sleep
• Wakefulness
• Hormone release
• Digestion

When your circadian rhythm is aligned, it generally results in greater sleep, energy, and overall health.

However, disruptions can lead to various issues tied to long-term health and disease risk and are backed up in other research  (Lunsford-Avery et al., 2018) (Trivedi et al, 2021). This includes;

• Increased risk of obesity & diabetes
• Mood disorders
• Weakened immune function
• Irregular blood pressure regulation
• Disruption in cellular repair processes

In other words, following a consistent sleep schedule can regulate your circadian rhythm, which is needed for optimized health.

What Does This Mean for Your Health?

This new research adds to our understanding of the importance of sleep. In addition to total sleep duration, it now seems clear that a consistent sleep schedule is just as important, if not more.

Therefore, aim for consistency while also optimizing duration using the 6-hour mark as your minimum threshold.

This information can actually be a relief to many individuals who struggle with getting a full 8 hours of sleep every night. Knowing that sleeping at the same time brings significant health benefits makes it possibly an easier goal for some people.

If you find yourself on the lower end of the sleep time spectrum, maintaining consistent hours could help offset some of the adverse effects. 

References

1. Lunsford-Avery, J. R., Engelhard, M. M., Navar, A. M., & Kollins, S. H. (2018). Validation of the sleep regularity index in older adults and associations with cardiometabolic risk. Scientific Reports, 8(1), 14158. https://doi.org/10.1038/s41598-018-32402-5 
2. Trivedi, R., et. al. (2021). Irregular sleep/wake patterns are associated with reduced quality of life in post-treatment cancer patients: A study across three cancer cohorts. Frontiers in Neuroscience, 15, 700923. https://doi.org/10.3389/fnins.2021.700923 
3. Windred, D. P., Burns, A. C., Lane, J. M., Saxena, R., Rutter, M. K., Cain, S. W., & Phillips, A. J. K. (2024). Sleep regularity is a stronger predictor of mortality risk than sleep duration: A prospective cohort study. Sleep, 47(1), zsad253. https://doi.org/10.1093/sleep/zsad253