Do steps and resting heart rate predict how fast you age?

A 2026 study matched smartwatch data against a DNA-based measure of how fast people are aging. Two of the clearest signals were numbers almost everyone already has on their wrist: daily steps and resting heart rate. People who walked more and had a lower resting heart rate tended to show a slower pace of aging.

The study is real, and the headline is fair. The size of the effect is smaller than the social posts suggest, and the design cannot show that walking more slows aging. It shows that people who walk more also tend to have DNA that looks like it is aging more slowly. Read the paper.

The practical takeaway does not depend on the aging clock. Steps and resting heart rate are worth watching because they track fitness and cardiovascular risk in much larger studies. If your steps are low, raising them is the cheapest change on this list. If your resting heart rate drifts up for a week, look at sleep, alcohol, illness, and training load before you look at anything else.

What the study found

Researchers at UCLA and the Precision Aging Network gave Garmin watches to adults aged 50 to 79 and took a blood sample from each one. From the blood they calculated DunedinPACE, a DNA methylation score that estimates how many years of biological aging a person is going through per calendar year. A score of 1.0 means one biological year per year. A score of 1.2 means about 14 months of aging in 12. In this group the average was about 1.05. How DunedinPACE was built.

621 people had both a blood score and watch data. The researchers checked about a dozen watch metrics against the score.

The paper reports two slightly different values for resting heart rate and blood oxygen in different sections. The table shows both.

Two details from the charts made the social media version of this study:

• Under 5,000 steps. Most people walked 3,000 to 10,000 steps a day. People under 5,000 showed up more often with scores above 1.2.
• Over 80 bpm. Resting heart rate ran from about 50 to 95 bpm. People above 80 showed up more often with scores above 1.0. That is close to the group average of 1.05, so it is a weaker signal than "accelerated aging" suggests.

What "11 fewer days a year" means

After adjusting for race, sex, and BMI, the researchers estimated how much the score moved per unit of each metric:

• About −0.01 per extra 1,000 steps a day. For 3,000 steps that is −0.03, or about 11 days less biological aging per year.
• About +0.003 per extra bpm of resting heart rate. For 10 bpm that is +0.03, also about 11 days.

These are separate estimates. They do not add up to 22 days, because people who walk more also tend to have lower resting heart rates, and the two measures overlap. The paper gives the figures as "approximately", so treat 11 days as a rough size, not a precise number.

For comparison, the CALERIE trial randomized 220 adults to two years of calorie restriction or their usual diet. Restriction slowed DunedinPACE, and the authors described the effect as small. The caloric restriction trial. That is one of the few randomized tests of this score, and even there the change was modest. Small changes in pace could add up over decades. You will not see them in a single year.

What the study cannot tell you

It is a snapshot. Each person was measured once, for about a week of watch data and one blood draw. The study cannot tell whether walking more slows aging, whether people who are aging faster walk less, or whether something else drives both.

The links are modest. A correlation of 0.25 means steps account for about 6% of the variation in the score. Most of what separated fast and slow agers was something else.

The groups were different in other ways. The fastest agers averaged a BMI of 30.4 against 24.3 for the slowest. Black participants made up 5% of the slow group and 46% of the fast group, a pattern earlier DunedinPACE research ties to social and economic factors. The model adjusted for race, sex, and BMI. It did not adjust for smoking, diabetes, medication, income, or neighborhood, and the authors say those matter.

It was exploratory. The authors tested many metrics without correcting for multiple comparisons and call the results hypothesis-generating.

The people were 50 to 79. If you are 28 and lift four days a week, you are outside the group that was studied. The direction of the findings is likely to hold. The cutoffs probably do not transfer.

The watch was a budget Garmin. Steps and resting heart rate from a consumer watch are reasonable. Overnight blood oxygen from a wrist sensor is noisy, and the authors say these readings are not clinical measurements.

Why steps and resting heart rate still matter

The reasons to care about these two numbers come from larger and stronger studies than this one.

Steps. A meta-analysis of 15 cohorts and about 47,000 adults followed people for a median of seven years. Compared with the lowest quarter (about 3,500 steps a day), people around 5,800 steps had about a 40% lower risk of death over the study. The benefit leveled off around 6,000 to 8,000 steps for adults over 60, and 8,000 to 10,000 for younger adults. Daily steps and mortality.

Resting heart rate. It falls as aerobic fitness rises, and a higher resting heart rate is a long-standing marker of cardiovascular risk. For lifters, it is also the number that moves first when recovery is off.

The aging study adds one more reason to watch these numbers. It is not the main one.

What to do with your own numbers

Use a weekly average. One day of steps or one morning's heart rate is too noisy to act on.

If you are cutting, more steps also raise your daily calorie burn. Adding them in the middle of a diet can make the deficit bigger than you planned, so watch the trend weight for two weeks. Should you eat back exercise calories? covers how to handle that. If you lift and wonder how much cardio is enough for heart health, cardio for lifters has the baseline.

When this is a medical question

See a clinician if your resting heart rate is regularly above 100 bpm, if it rises with chest pain, shortness of breath, dizziness, or fainting, or if your overnight oxygen readings are often below 90% alongside loud snoring or gasping. A smartwatch is not a diagnostic device, and the study authors make the same point.

A DNA methylation test bought online is not a reason to change medication or treatment. These scores are research tools. They are not validated for individual clinical decisions.

Common questions

Can 3,000 more steps a day add 11 days to my life?

The study did not measure lifespan. It estimated that people with 3,000 more daily steps had a DunedinPACE score about 0.03 lower, which works out to about 11 fewer days of biological aging per year. It measured each person once, so it cannot show that adding steps would change your score.

Is 10,000 steps the target?

Not necessarily. The meta-analysis authors note that 10,000 is widely promoted with little evidence behind it. In their data, most of the benefit came by 6,000 to 8,000 steps for adults over 60 and 8,000 to 10,000 for younger adults.

Is a resting heart rate of 80 bad?

Not by itself. In this study, values above 80 showed up more often with a slightly above-average aging score. A normal adult range is usually given as 60 to 100. If yours sits near 80 and you do little cardio, aerobic training is the usual way to bring it down.

Do I need a biological age test?

No. A blood test costs money and gives you one reading. Steps and resting heart rate are free, update every day, and are already linked to health outcomes in larger studies. Use those.

I lift four days a week. Do my steps still matter?

Lifting and steps measure different things. A lifter can train hard for an hour and still sit for most of the rest of the day. In this study, more sedentary time went with faster aging. In the mortality research, once total steps were accounted for, time spent walking briskly was no longer a significant predictor, so ordinary walking counts. If your weekly average is low, walks on rest days are the easiest fix.