STAT - Ruth Hailu: Fitbits and Other Wearables May Not Accurately Track Heart Rates in People of Color

30 July, 2019

Dear all,

Wearable technology could save lives.  How could this technology be improved to be inclusive?  See an update by Apple at the end of the article.  Here is the full article by Ruth Hailu of Harvard University.  


HIFA profile: Enku Kebede-Francis (PHD, MS, MEd) is an advisor in global health governance. She has worked for the United Nations (UNESCO, UNDP, UNFPA and UNDPI); was an Assistant Professor at Tufts University Medical School/Department of Public Health; and, a Visiting Scientist at the USDA’s Center for Human Nutrition Research Center for Aging and a Visiting Fellow at the Australian National University Medical School. She also designed and implemented preventive health programs promoting women’s health and tobacco cessation programs in Croatia and worked on addiction prevention programs in Florida and Massachusetts, USA. Her professional interests include preventing scurvy and childhood blindness in developing countries using micronutrients. An advocate for primary healthcare for all as a right, she published a textbook in 2010, Global health Disparities: closing the gap through good governance.


Fitbits and other wearables may not accurately track heart rates in people of color

By RUTH HAILU @ruth_hailu_JULY 24, 2019

[*Note from HIFA moderator: full text here: ]

An estimated 40 million people in the United States have smartwatches or fitness trackers that can monitor their heartbeats. But some people of color may be at risk of getting inaccurate readings.

Nearly all of the largest manufacturers of wearable heart rate trackers rely on technology that could be less reliable for consumers who have darker skin, according to researchers, engineers, and other experts who spoke with STAT. Fitbit uses the potentially problematic technology in every heart rate tracker it offers, and it’s also in many Garmin and Samsung devices. Other popular trackers, like the Apple Watch, use it, too — but simultaneously track heart rates with another method.

The phenomenon has received almost no media attention, even as the market for smartwatches and fitness trackers has grown exponentially in recent years — and as both consumers and scientists have raised broader concerns about the trackers’ accuracy. There are a number of online complaints from consumers who suggest the devices can’t get a reading on darker skin. But the companies that make the devices don’t disclose the fact that they could be less accurate for some consumers.

The potential inaccuracies have broad implications for the growing body of scientific research that relies on these wearables — as well as for the increasing number of people whose employers offer financial incentives or other benefits for using Fitbits and other trackers.

Concerns about the devices also come amid a broader reckoning over whether new technologies are as objective as they appear — and whether implicit prejudices are shaping their development.


Since he abandoned his Fitbit, Ross has switched to using an Apple Watch to track his heart rate. He thinks it’s more accurate — but he’s not sold on whether either is as good as just calculating his pulse with a timer.

“I do use it to monitor heart rate … But I also manually check my heart rate to make sure that I know exactly what my heart rate is,” he said. “It’s a good tool, it’s just not something you should depend on.”

Researchers echoed the same sentiment — that the tech is useful, but perhaps not as well-studied as it should be.

“These technologies are really being used so that we can collect heart rate out in real-world environments. Technologically, it’s one of the few ways that we can do it right now,” said Nelson, the postdoctoral candidate in Oregon. “So while there are a number of really important limitations that should be paid attention to by scientists, including things like skin tone, body mass index, and wrist circumference, it’s kind of the technology that we have right now.”

This story was updated after Apple clarified that it used infrared light in its devices for periodic heart rate monitoring, not to address the way melanin in skin absorbs green light, and to include statements from Fitbit officials.