Ask Dr. Denise Dennis-Coke about health-tracking devices, and she’ll show you the ones she’s wearing.

“I have on my Dexcom Stelo, my Oura ring and my Garmin watch,” she says with a chuckle. “For me, it’s like, ‘Let’s see what the data says, and then let’s see if we can improve it’ — which is how I would recommend most people approach it.”

Like doctor, like patient. Dennis-Coke is an obesity medicine physician and medical director for the CoreLife Novant Health Charlotte region. For the past decade or so, as both a consumer and a physician, she’s observed the rocketing development of wearable tech that tracks health metrics — Apple, Samsung, Garmin, and Fitbit smartwatches and Oura smart rings, not to mention glucose monitors like Dexcom G7s and Stelos and Abbott Lingos.

The devices fall into three main categories:

• Fitness trackers, like smartwatches, that monitor daily movement, heart rate and workouts
• Smart rings, which measure sleep, heart rate and temperature
• Glucose and metabolic sensors, which track blood sugar and provide real-time insights into metabolism

With current and anticipated AI advances, wearable technology is expected to swell from a $70 billion global industry in 2024 to $153 billion by 2029.

Yet Dennis-Coke emphasizes that not every device works to enhance every patient’s health — and some people might be better off with no device at all.

“We already are in an era of screen and notification fatigue, and when you add your health data on top of that, that can be quite anxiety-provoking for some people and fatiguing for others,” she said.

Dennis-Coke added that she’s fallen victim herself: She’s awoken in the middle of the night and reached for her smartphone to open her Oura app — the companion app for the titanium Oura ring, a smart ring that tracks sleep and other health metrics. In other words, she’s interrupted her sleep to check the data that shows how well she’s sleeping, which defeats the purpose of tracking sleep data.

Because of her experience on both ends of the wearable tech equation, we asked Dennis-Coke to answer some basic questions: Which devices are available, who are they best suited for, and what’s to come in the years ahead?

What are the most common health tracking devices?

The first category would probably be your fitness and activity trackers, like the Apple Watch, the Samsung watch, the Garmin, the Fitbit. The Fitbits probably were the first of this generation. These monitor basic activity levels. You can track your performance. You can track steps.

From there, we have glucose monitoring and metabolic monitors, like the (Dexcom) G7, the Stelos, the Abbott Lingos — there’s quite a few of them. (They work by using a tiny sensor wire just under the skin, typically placed on the back of the upper arm, to measure glucose levels.) Some platforms have built AI integration into those devices, and they use the data collected to give you guided coaching.

Let’s say your glucose spikes after you eat a certain type of food. These devices can use that information to suggest better options. AI features started appearing in these systems two or three years ago, and they’ve been steadily improving ever since.

These devices seem to track amazingly precise health and fitness data. How much attention should people pay to the numbers?

The goal is not necessarily to get into the granularity of it. You want to take more broad strokes. You want to attach this to some kind of targeted goal.

For example, if I’m concerned about my sleep, I would say, ‘Let’s see how many hours of sleep I’m getting. Let’s look at advice from a medical perspective on how to improve my sleep. Can I see a little bit of progress in that area?’ So it’s more that sort of thing — not so much to know exactly how my body’s functioning every minute of the day.

Generally, what are the benefits of health tracking devices?

I always say, all behavior change starts from knowing what those behaviors are. You can only change what you’re aware of. You can build on top of that, motivating your daily habits. For some people who are recreational athletes, it can help them track their performance. It can help you to track your sleep, your stress, your recovery (from workouts), and things like that.

We’re also seeing some of these platforms integrating with each other. The first device I got was my smartwatch, but I ended up getting the Oura ring when it did an integration with Dexcom (which measures glucose levels). So now you have your glucose data coming into your movement data, and you can look at those things together — like, how do my glucose patterns vary based on my movement patterns?

What are some of the disadvantages and risks of health tracking devices?

There are some privacy concerns. This data is all warehoused by these big companies, and it can be sold. You don't know who it’s going to. How’s it going to be used? How’s it being shared?

There are some accuracy issues, too. This is one of the reasons why I believe it should be used more as a broad estimation of what’s happening and not so much like a granular, detailed tracking. There’s variability, and there are inaccuracies sometimes in how some of this data comes through or is measured.

You just want to be careful with some of this information. You wouldn’t want to start restricting a whole macronutrient like carbs because you’re seeing glucose spikes every time you eat something with carbs. It probably would make more sense to have that conversation with your healthcare provider and be mindful of not restricting your diet too much as a result of the data that you’re getting.

And if you have a serious health condition such as diabetes or an arrhythmia, I would definitely monitor that under a medical provider’s care. I would not use a consumer device for that.

How much will AI influence the future of health tracking devices?

As AI continues to improve, more people are likely to use health tracking devices that include these features. Interestingly, now they’re also looking at diagnostics — devices that can detect symptoms before they even start to appear. The Oura ring does a little bit of this, because sometimes it’ll tell you, based on your biometrics, that you might be coming down with an illness.

So I think that's going to potentially be a big thing. I think there's just going to be more to come in this area.

As a general rule, which health tracking devices are best for which kinds of health goals?

If you’re a runner, probably a Garmin. If you’re just a general walker, mover, exerciser, maybe you’ll be fine with your Apple Watch or Samsung or Fitbit. It just really depends on the person. For people with blood glucose issues, probably the Dexcom and Abbott blood glucose monitors, and to track sleep and optimize performance, the Oura ring or WHOOP (a fitness tracker worn on the wrist).

But I’d encourage people not to just jump on a trend. There’s no one-size-fits-all.