The first fitness tracker you ever owned — whether an early Fitbit, the now-defunct Jawbone, a simple pedometer or a heart monitor strap — probably did little more than track your steps and calories burned. Early smartwatches, meanwhile, essentially felt like phone companions rather than standalone devices.
But fast-forward to 2022 and a lot has changed. Wearables are no longer niche devices for early adopters or fitness fanatics. The Pew Research Center reported in 2020 that about one in five US adults regularly wears a smartwatch or fitness band. Global smartwatch shipments grew by 47% annually in the second quarter of 2021 according to Strategy Analytics, signaling the industry’s fastest growth rate since 2018.
Today’s wrist-worn devices are comprehensive fitness gadgets capable of taking an ECG reading from the wrist, monitoring sleep quality and measuring blood oxygen saturation, among other things. That opens up a world of opportunities but also makes things complicated. We have more access than ever to data about our heart rate, how much sleep and activity we’re getting and our overall well-being. Yet some newer, more advanced health metrics can be challenging to comprehend, raising the question of whether they’re truly helpful.
Therefore, context and personalization will be key to both current and next-generation wearables, according to conversations with medical experts, tech executives and industry analysts. The medical community is also excited about the potential that future fitness devices hold for detecting more advanced metrics, like changes in glucose levels and the role of wearables in preventive care.
Making better sense of health data from our fitness trackers
The biggest improvements that are likely to arrive in the near term will involve making health data more useful and personalized. Oura, Whoop and Fitbit are already helping steer the industry in this direction with their respective scoring systems, some of which require a paid subscription.
Both Oura and Fitbit, for example, offer readiness scores that help wearers decide whether it’s time for a heavy workout or a rest day. Those numbers are based on metrics such as resting heart rate variability, sleep, activity and other bodily signals. Whoop has a similar recovery score that provides insight on whether a user’s body is ready for strenuous exercise.
Oura’s readiness score embodies the company’s overall approach to health tracking, which is that devices should provide context alongside numbers and data points, according Chris Becherer, Oura’s chief product officer. He added that Oura will maintain that approach with newer features, such as the period prediction tool it launched in October, and will only expand into new types of health tracking if the company can provide similarly helpful insights.
“We won’t do it just for the sake of doing it,” Becherer said. “And we’ll make sure that it fits with the holistic user-friendly experience that Oura is known for.”
Fitbit sees another opportunity for adding more personalization and specificity to health metrics: exploring the link between mental and physical wellbeing. Fitbit is already dipping its toes into mental wellness with its EDA app, available on the Fitbit Sense and Charge 5, which measures changes in sweat to see how the body might be responding to stress.
Fitbit also lets wearers log their mood to accompany those readings, so users can see how they felt when the measurement was taken. Analyzing that type of data over time could help Fitbit better understand what bodily changes mean for a person’s overall wellness, allowing for more thorough insights.
“We can over time get more and more correlation between this idea of, ‘How do I feel?’ compared to ‘What is my physiology and what are the metrics telling me?'” said Jonah Becker, Fitbit’s design director. “Which I think is a powerful thing.”
The ability to measure additional body signals, such as electrodermal activity (i.e., the EDA app’s sweat readings), could also lay the foundation for future Fitbit features. Eric Friedman, Fitbit’s co-founder and vice president of research, points to Fitbit’s sleep stages functionality as an example. That feature, which tells the wearer how much time was spent in light, sleep or REM sleep, is only possible because of other metrics that came before it, like heart rate and motion measurements.
“Imagine taking that and EDA, and you … start building things together to start layering these health metrics on top of each other, going to the next thing,” Friedman said.
Blood sugar monitoring could be the next major step forward in health tracking
What exactly that “next thing” is remains unclear. But reports and expert predictions do point to blood sugar monitoring in wearables as an area of interest.
However, that doesn’t mean diabetics will be able to rely on smartwatch readings to calculate insulin dosages. That will still require more invasive devices that break the skin for the foreseeable future, says Dr. Steven LeBoeuf, president and co-founder of Valencell, which makes health sensors for wearable devices.
Instead, a future glucose-monitoring smartwatch might be able to make broader observations about whether the wearer is in a state of low, normal or high blood sugar. That could help wearers understand whether diet or exercise changes are impacting their blood sugar, or whether the user should use a glucose meter, says Dr. LeBoeuf.
“Now that has all kinds of positive implications,” said Dr. LeBoeuf. “So I think you will be seeing that technology in wearables as well, whether it comes from Valencell or some other entity.”
Dr. Zahi Fayad, director of Mount Sinai’s Biomedical Engineering and Imaging Institute, also sees a lot of potential in this space. Glucose monitoring capabilities like those mentioned above could help wearables offer more personalized nutrition advice. That’s important because today’s recommendations are typically based on broad population studies and therefore lack customization according to Dr. Fayad.
“Everybody’s gut microbiome is different and reacts to food differently, or reacts to lifestyle changes differently,” said Dr. Fayad.
Yet it’s unclear when or if this type of functionality will arrive in everyday smartwatches or fitness trackers. Apple has been working on adding blood sugar monitoring to the Apple Watch, according to reports from Bloomberg and The Wall Street Journal, although both reports suggest the technology is in its early stages.
Roberta Cozza, a senior director analyst at Gartner, thinks there is still a long way to go. Although research is being done in this area, she believes accuracy and medical clearances present a challenge.
“I think for this, you’re going to have to have something that is medical-approved,” she said. “So it’s going to take some time until we find something that is really usable and reliable.”
Smartwatches and fitness trackers are already starting to blur the line between medical and wellness devices. Adding more sophisticated metrics, like glucose readings, means tech companies will have to be mindful about how users may interpret these readings.
“Maybe vendors need to find new ways in which they can be clearer with consumers around the expectations that they might have when wearing some of these devices,” said Cozza. “Because this will be getting just more and more complicated.”
Filing in the gaps between doctors visits
The medical and tech communities seem to share a common goal when it comes to progress in the wearables field: Helping people take better care of themselves between doctor’s appointments.
“Instead of having one data point per year, you have continuous data points across every single part of your day,” Oura’s Becherer said.
That’s part of the inspiration behind new features and capabilities that have arrived in recent wearable devices. For example, Amazon’s Halo health app includes a tool for estimating your body fat percentage based on images taken from a smartphone’s camera, which it analyzes using machine learning and computer vision. The feature has been somewhat controversial when it comes to personal privacy.
But Melissa Cha, vice president of Amazon’s Halo division, says the goal behind this feature is to help people to keep a log of their bodily changes — another tool for monitoring progress between doctor’s visits.
“You have a long-term record that you can then share with your care provider or physician if you want to discuss changes in your body composition over time,” Cha said.
Dr. Devin Mann, associate professor of population health and medicine at New York University Langone Health, believes we’re seeing more of a crossover between medical and consumer devices. That’s because each side has something to learn from the other.
Commercial wearables are gaining more advanced health monitoring capabilities, while medical device makers are trying to reach broader audiences.
“We’re sort of seeing those two streams coming together,” Mann said. “And there’s more overlap between them.”
Over the long term, some experts are excited about the potential of using wearable devices to help detect disease early. That type of functionality is still in its early stages, but Dr. Paul Friedman, a cardiologist in the Mayo Clinic’s AI in Cardiology Work Group, is encouraged by the progress the industry has made so far. A few years ago, most physicians wouldn’t have trusted the data from health trackers to help inform medical treatments, according to Dr. Friedman. But that’s changing.
“The answer would have been no; nine out of 10 when they were surveyed said no,” Friedman said. “Now it’s almost reversed.”