We often hear that healthy aging depends on how much we exercise and how well we sleep.
But another factor may matter too:
how regularly our days are organized.
A 2026 study found that people with stronger and more stable patterns of activity and rest tended to show less epigenetic age acceleration.
In other words, the regularity of our daily rhythm may provide information about how we are aging biologically.
What Is a 24-Hour Activity-Rest Rhythm?
Your body follows a daily rhythm.
You are generally more active during certain parts of the day and less active during others. Sleep forms part of this pattern, but the rhythm includes the whole 24-hour cycle, not sleep alone.
Researchers can measure this using a wrist activity monitor.
In the study, 207 adults with an average age of about 68 wore these monitors for seven days.
The researchers examined how strong and regular their activity-rest patterns were and compared them with biological-aging measures from blood samples.
How Was Biological Aging Measured?
The researchers examined patterns of DNA methylation — small chemical changes to DNA that can be used to estimate aspects of biological aging.
They used four different epigenetic clocks.
These clocks do not all measure exactly the same thing, which is why their results can differ.
The clearest relationships with daily rhythms were found with two of them: GrimAge and PhenoAge.
The important overall finding was simpler:
people with stronger and more stable daily rhythms tended to have more favorable epigenetic-aging profiles.
Consistency From Day to Day May Matter
One of the clearest findings involved how consistently a person’s activity-rest pattern repeated from one day to the next.
Greater day-to-day stability was associated with less epigenetic age acceleration.
By contrast, more fragmented and irregular activity patterns were associated with less favorable results on some of the biological-aging measures.
This suggests that healthy aging may be related not only to what we do, but potentially also to how consistently our activity and rest are organized.
Does This Mean You Should Follow the Same Schedule Every Day?
Not yet.
The study found an association. It did not test whether deliberately making people’s daily routines more regular could slow biological aging.
It also cannot tell us which came first.
Irregular rhythms could potentially influence aging. But poorer health or more advanced biological aging could also make daily rhythms less stable.
So we should not turn these findings into a prescription for a rigid daily schedule.
Is There an Ideal Time to Sleep or Exercise?
The study does not provide a simple answer such as “earlier is better.”
Relationships involving the exact timing of activity and rest were more complicated and sometimes differed with age.
The more consistent finding concerned the strength and stability of the overall 24-hour rhythm, rather than one perfect bedtime, wake-up time or exercise time.
Why Does This Matter for Longevity?
The body is organized around circadian rhythms that help coordinate sleep, metabolism, hormones, cardiovascular function and many other biological processes.
This makes daily rhythmicity an interesting area of longevity research.
But there is an important distinction:
a marker of healthier aging is not automatically a method for slowing aging.
Larger and longer studies — particularly intervention trials — are needed to determine whether improving daily rhythm regularity can actually influence biological aging.
