Should everybody really be wearing a fitness tracker?

A decade ago, only step-count fanatics wore fitness trackers. Today, trackers are as common as gym memberships—and soon, everybody might be wearing one.

During a recent House committee hearing, Robert F. Kennedy Jr.,  head of the Department of Health and Human Services, laid out a vision to get every American using a fitness tracker within 4 years.¹ 

“We’re about to launch one of the biggest advertising campaigns in H.H.S history,” said Kennedy. And the goal will be “to encourage Americans to use wearables.”

It’s an ambitious plan. And it raises a question: Should everybody really be using a fitness tracker? 

As it stands now, healthier people are more likely to use wearable fitness devices. 

• A 2023 JAMA study found that among the general U.S. population, nearly 29% of people use trackers.² 
• Among those with cardiovascular disease, usage falls to 18%.

But just because healthy people use fitness trackers does not mean that fitness trackers improve health. It’s the difference between correlation and causation. 

To understand the impact of fitness trackers, we sat down with Renee Deehan, PhD, InsideTracker’s senior vice president of science and artificial intelligence. 

Deehan is an avid fitness tracker user, and for the past decade, she’s been driving the development of new technologies to improve health and longevity. 

So, should everybody really be wearing a fitness tracker?

Renee Deehan, PhD: Fitness trackers can be great. I personally find them helpful—and lots of other people do too.

That said, I don't think it's a requirement that everybody wear one. You can be a healthy person without one, so it's really a personal decision.

What would be a drawback to wearing one?

RD: For some people, fitness trackers may cause health anxiety. That’s especially true if you have problems you can’t easily fix.
 
Say you're a caretaker looking after your aging parents. You're under a lot of stress and you’re not getting a lot of sleep. In that case, having a fitness tracker to tell you that you’re stressed and tired may not be helpful. There just might not be a lot of room in your life to do anything about it. 

There’s also a criticism that sleep trackers in particular can lead to sleep obsession. People fixate on their lack of sleep, and that leads to anxiety that makes it even harder for them to fall asleep. 

If that’s your experience, maybe the tracker just isn’t for you. Or you just need to take a break.

And then, of course, there’s cost. Fitness-tracker prices are coming down for entry-level models, but they can still be expensive.  

So who should wear one? 

RD: If you’re already motivated to be healthier, and you’re curious about your data, a tracker can be really useful. Today’s trackers go way beyond steps. You’ll also see things like resting heart rate, heart-rate variability [HRV], and VO2max. 

But if you’re not motivated, and you’re not curious, then it’s not going to hold your attention long enough to do something with. 

A lot of people buy fitness trackers, wear them for a little bit, and then throw them in a drawer. What good is that?

For those who wear them, do these devices actually work? 

RD: They can, but it’s helpful to parse this into two questions.
 
First, are they tracking meaningful information? And for the most part, the answer is yes. These are well-studied aspects of health. 

For instance, a higher step-count is correlated with better health outcomes. And a lower resting heart rate is associated with a lower risk of cardiovascular disease. So this is good data to have. 

Second, are fitness trackers improving your health? That’s a trickier question that has to be answered by looking at individual markers. 

Take sleep tracking. It can help some people, but as I mentioned, it can also make sleep worse for people prone to sleep anxiety. Overall I wouldn’t say there’s good evidence that simply wearing a fitness tracker that tracks your sleep will actually help you sleep better.

But for step count, we do see some benefit. One large research review found that wearables increased steps by about 1,800 steps per day.³

There are other reviews that find lower numbers,⁴ but it seems clear that there is some positive effect. Steps is the original fitness-tracker marker, so we have some of the best research there. For newer wearable markers, we can still use more data.

>> Related: Do you actually need to take 10,000 steps a day?

Are fitness trackers accurate?

RD: If you ever wear multiple trackers, you’ll notice there’s some discrepancy. Maybe your step count on one is 2,000 higher over the course of a day. 

But really, it’s not too big of a deal. The important thing is to pick one tracker and compare yourself over time. You just want to make sure you’re either maintaining or improving.

How does InsideTracker make fitness tracker data useful? 

RD: InsideTracker is all about showing you how to improve. We don’t just ingest data and show it back to you in a pretty format. We turn your data into lifestyle recommendations.

So instead of just reporting your stats, we’ll give you dietary changes, supplements, exercise, and other lifestyle interventions like sleep or meditation to combat stress. And it’s all personalized.

>> Related: How Your “Healthspan Habit Report” Makes You Healthier Every Week

InsideTracker looks at DNA and blood results alongside fitness tracker data. Why?

RD: The InsideTracker approach is that we don't really care where the data comes from as long as it’s high-quality data. 

It can come from a fitness tracker, blood, or DNA. We also use survey data; we can get a ton of information about somebody just from asking them questions.

Fitness trackers are a really valuable data stream to have in the mix. It’s continuous, so you get daily information. And it can be collected very easily. You don't have to get stuck with a needle or send in a cheek swab; you just put a tracker on your wrist or finger. 

That has a lot of value. But it’s even better when we combine that with other information. It lets us make connections between your daily activity and your blood biomarkers. 

>> Related: How an InsideTracker Membership Uses Data to Add Healthy Years to Your Life

I'll give one example from a study that InsideTracker did on its participants. 

We looked at people who had unoptimized LDL for their first blood draw. These people split into two groups over time: For some, LDL stayed the same or got worse, while for others, they managed to lower their LDL in subsequent blood draws.
 
So we asked, “What is the difference between these groups?” And one thing we saw is that the LDL improvers actually started taking more daily steps. 

That was not a randomized control trial, but there’s a correlation there. The people who walked more improved their LDL cholesterol. We could see that clearly in the data. That’s pretty cool. 

So there’s a biofeedback loop that lets people see the impact of their habits. 

RD: Absolutely. Because without blood data, your step count is going into a black hole. How do you know if it's actually improving anything or not? 

If you put in the work, you want to see the impact. You want to see your blood biomarkers moving toward optimization.

It's really about building a high-resolution picture of somebody's health from the different types of data we collect, and then connecting the dots to show what they need to do next. 

>> Related: Here's What You Need to Know About Your Running Heart Rate

What changes will we see with fitness trackers in the next 3 to 5 years? 

RD: Fitness trackers will continue to measure more markers. 

Hydration monitoring is one measurement on the horizon. And companies are currently developing cuffless blood pressure monitoring and blood glucose monitoring that doesn’t have to prick the skin. 

Something I'm super excited about is continuous lactate monitoring. So you can look at this while you work out to determine how much effort and intensity your body is producing. 

So if you're trying to do a long endurance event and you want to keep your lactate production low, you'll be able to monitor that throughout your run or ride.

Are there people who should avoid fitness trackers? 

RD: If your fitness tracker is stressing you out, it’s probably not for you. Or you can wear the device for a little while, get a sense of where you’re at, and then take it off for a while. That’s fine. 

But other than that, they don't hurt, right? They are entirely non-invasive. If you like looking at the data, then go for it.

I was an early adopter of Oura, and I have been looking at my sleep and HRV data for 6 years. In that time, I’ve improved both. 

My HRV has gone up, and I’ve slowly been able to improve the amount of sleep I get. I started at something like 5 hours and 45 minutes, and now I'm at almost 7 hours a night.
 
That’s a meaningful improvement, so wearing a fitness tracker has been a net positive for me. I just think there’s a lot of good that can come from these devices.

InsideTracker syncs with Fitbit, Garmin, Oura, and Apple Health. Learn more here.