As smart watches and other wearables provide users with sensors to monitor their fitness and health, they are generating a treasure trove of data. But whether all of this information actually contributes to a healthier society is up for debate.
While there has been a surge of interest in wearables, there isn't definitive evidence they are having a positive impact on people's health. In fact, some researchers and technologists warn wearables may not be providing insights they need to make positive lifestyle changes, but instead are overloading users with health metrics and notifications.
Sensors driving adoption
On a global scale, the International Data Corporation's (IDC) Worldwide Quarterly Wearable Device Tracker found that the wearables market grew 35.1 percent year-over-year during the third quarter of 2020, with 125 million shipments. The firm estimated an overall shipment of 396 million devices in 2020 — up 14.5 percent year-on-year — led by products from Apple, Xiaomi, Huawei, Samsung, Fitbit, and BoAt.
That increase in sales may sound surprising in a year when many consumers had to cut back on spending. But as sensors have gotten smarter and wearables more attractive, consumer interest has grown, led primarily by purchases of smart watches, wristbands, and earwear.
"Two or three years ago, there was a lack of understanding why consumers were buying [wearable] devices,” says Francisco Jeronimo, associate vice president for European devices at IDC. “Vendors were basically bringing all sorts of features to devices because no one really knew what the killer app was,"
The "killer app" turned out to be equipping consumers with exercise and sports metrics. "That's when we saw the likes of more sensors being brought to watches and wristbands," says Jeronimo.
Recent years have seen new sensors introduced to track metrics such as fitness activity, steps, time spent sitting/standing, active calories burned, sleep, body temperature, and beyond. This year the Samsung Galaxy Watch3 added a sensor to measure blood oxygen levels. A recent software update also introduced a new cardio fitness score that uses a person's VO2 max — maximum oxygen consumption during exercise — to gauge their cardiorespiratory health.
Some devices can even tell you how stressed you are. The new Fitbit Sense, for example, has an electrodermal activity (EDA) sensor that calculates a "stress management score" using sleep data, heart rate, and activity data. Scores range from 1-100; the higher the number, the fewer physical signs of stress someone is showing. Along with the score, the Sense also provides stress management recommendations, like breathing exercises.
Another significant development has been the introduction of an FDA-approved electrocardiogram monitoring (ECG) sensor and app on Samsung, Apple, and Fitbit watches, to allow wearers to monitor their heart rhythm for irregularities.
IDC's Jeronimo says these sophisticated sensors are leading to greater consumer demand: "Smart watches are growing the fastest and providing more value to end users because the amount of data you can get is fundamental to help you monitor your healthcare," he says.
Indeed, another way wearable data might be more useful is in collaboration with healthcare providers. Doctors could use their patients' fitness data to help them develop healthier habits and understand what their metrics mean for their lifestyle, health, and wellness, for example. Having real-time access to patient health data could also be useful in providing treatment via telehealth.
"We've started to see, from different healthcare providers, the launch of services apps that would allow doctors to get access to that data," says Jeronimo. "That's when it becomes really interesting. It's not just me seeing how much physical activity I've done, it's my doctor looking into that and trying to make sense of it."
Too much data, not enough insight
While many tout the actionable insights that could come from a multitude of new wearable sensors, having too much data might actually demotivate some smartwatch wearers, says Dr. Zakkoyya Lewis, assistant professor in the department of kinesiology and health promotion at California State Polytechnic University.
"From a motivational point of view, too much data and self-monitoring can be counterproductive because the wearer will be active for the data and not for the sake of being active," says Lewis. "In other instances, tracking data can be counterproductive and de-motivating if the wearer is not meeting their goals."
In addition to potential de-motivation, Lewis says that by tracking so many metrics – such as calories burned, exercise minutes, distance, floors climbed, heart rate, sitting/standing time, and steps per day – it's easy to overload users with numbers instead of comprehensive insights.
For wearables to be effective, they need to not just be data trackers, but a motivating force. "Some wearers can become easily fixated on all of the data metrics instead of focusing on the one or two that are the most meaningful to them," she says.
Another issue, says Lewis, is that vendors track and deliver metrics differently and aren't always clear about what certain numbers mean. One example is energy expenditure, or calories burned, and the difference between "active" calories burned – such as during exercise – and "total" burned, or energy used just by existing. While some devices measure both, others offer just one or the other.
"If a device estimates total energy expenditure, some wearers may interpret that as the calories burned from a workout. Which is incorrect and can be confusing," she adds.
Meanwhile, Dr. Dan Ariely, a professor of psychology and behavioral economics at Duke University, concurs that too much data, and a lack of clarity around it, can be overwhelming and counterproductive.
"If you tell me, 'you're not walking enough, and you're eating too much of this, and you're too exposed to electromagnetic radiation, and you're not standing enough, and you're drinking too much coffee, and your heartbeat is irregular…' I look at all this and say, you know what, anything I would do is a drop in the bucket. I could never conquer this," says Ariely.
Ariely is also the founder and chief behavior officer at Shapa Health, a connected health company that helps people achieve weight loss goals by delivering data and insights differently.
Through a combination of its own numberless scale, fitness data from sensors, and personal assessments filled out by users, Shapa creates a daily program of activities specific to individual lives, personalities, and habits. It then tracks their progress and delivers feedback on their weight loss goal through the Shapa app, using a color code instead of a weight number.
According to Shapa Health founder and CEO Nati Lavi, the company's incentives-based reward and feedback model has resulted in daily engagement of nearly 86 percent over 12 months for average users. He says that seeing improvements in their health outcomes enables people to stay engaged and solidify positive behavior changes.
Ariely adds that players in connected health need to focus on behavioral change, not data. "If we want to understand how people can change behavior, it's not about what they're doing now, it's about what they could be doing."
"Smart watches are growing the fastest and providing more value to end users because the amount of data you can get is fundamental to help you monitor your healthcare," - Francisco Jeronimo, VP, European Devices, IDC
Addressing data inequality
But as device makers and developers seek to add myriad sensors and apps to equip people with metrics to get healthier, it's important to ensure that health data is being gathered and delivered equitably. Researchers say we aren't there yet.
One issue Lewis highlights is how wearables quantify metrics for an "average" individual. "In most cases, this 'average' individual falls within the following demographic: college-age or middle-aged, White, male, college-educated, overweight," she says.
While wearable devices account for an individual's metabolic rate using a variety of factors – including body mass index (BMI), age, and sex at birth – many of these equations don't factor for different races and ethnicities.
"Some research suggests that body composition differs between different race and ethnicity groups and this has a direct impact on resting metabolic rate. In other words, racial and ethnic minorities do not get the most representative data," says Lewis.
Another study, entitled "Limiting racial disparities and bias for wearable devices in health science research," and published in the journal Sleep, raises an important issue with green light sensor technology used in wearables. The authors of that study note that there is growing evidence green light technology does not work as well with darker skin tones.
"Skin tone affects the absorption of light differently, which interferes with the algorithm output," says the report. It goes on to note that research suggests green light "may not read at all when measuring heart rate in darker skin types."
For better insights, make it personal
To address data inequality and provide more meaningful insights for all users, researchers say that companies working on wearables will need to offer a comprehensive analysis of health metrics, along with personalized behavioral motivators.
Dr. Lukasz Piwek, a psychologist and lecturer in data science at the University of Bath, envisions a future where fitness and health information is gathered from multiple, interconnected devices and services to form a holistic picture of individuals and how they spend their time to better deliver health insights.
"It will create a more comprehensive picture of what our health looks like, and where this feedback and those prompts could come in to make some meaningful impact," he says.
In other words, rather than nudging a user to go for a run while they're in the middle of a meeting, based merely on their activity stats for the day, for example, a future wearable platform would also have awareness of a person's calendar and social network to be able to suggest they exercise at an optimal time, and perhaps even encourage them to go for a run with a nearby friend based on location data.
"When we talk about wearables, this definition will completely expand into almost anything that we use or wear," adds Piwek.
Toward even smarter wearables
With consumer interest in fitness trackers on the rise, device makers and developers have a unique opportunity to meet that growing demand with products that have the power to create a healthier society. However, to achieve that goal, researchers believe the industry must evolve beyond delivering a barrage of numbers and begin thinking about ways to account for the full individual, which could include their race and ethnicity, lifestyle, health motivators, and beyond.
While the past few years of wearables have been about equipping people with as many sensors and as much information as possible, health and behavioral experts hope to see the industry focus more on providing relevant and actionable insights, and less on overwhelming people with data. That combination of data and insights might just be the tipping point between wearables for early adopters and widespread consumer interest.
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