Wearable devices are all the rage these days, promising to monitor physical activity, sleep, and other types of human movement. While these wearable activity trackers may be good at tracing your steps, they may be bad at measuring your sleep, as discovered in a new study.
Researchers from the UNC Gillings School of Global Public Health and RTI International, who published their findings on Dec. 18 in the International Journal of Behavioral Nutrition and Physical Activity, found that these wearables do a better job of measuring some metrics than others.
The study led by Dr. Kelly Evenson, epidemiology research professor, reviewed 22 published articles to assess the performance of popular wearable trackers Fitbit and Jawbone in measuring distance, steps, calories, physical activity, and sleep.
"We conducted this review to understand how accurate these devices are," said co-author and senior clinical informaticist Dr. Robert Furberg.
What Can These Trackers Do?
The systematic review found that these trackers had higher efficiency in step counting and lower validity for calories and sleep. Findings on distance and physical activity, however, were based on few studies and were thus inconclusive.
A number of studies in the review indicated that the trackers' step-counting was accurate both in the lab and field, with only one study noting that Fitbit tends to overestimate at slower speeds and underestimate at the opposite.
Other researchers, using different comparison techniques, discovered that both Fitbit and Jawbone overestimated total sleep time. Caloric expenditure, on the other hand, was over- and underestimated.
How Trackers Can Step Up
"[W]e learned several tips users may be able to implement to make their tracker more accurate," said Evenson said, who recommended the following tips to device wearers:
Wear the device in the same position every day.
Input personal details such as weight and height correctly upon initial setup. Update any significant change in weight.
If the tracker has the following options, then make sure to:
Correctly calibrate a walking stride's length.
Add more details through the journal feature.
Dabble with the sleep mode settings.
The Future Of Wearables
Next-generation wearable technology is noteworthy, bringing humans closer to a future of bionic, in-body tech tools and devices.
Google partnered with jeans brand Levi Strauss & Co in developing clothes that interact with devices, featuring touch-sensitive surfaces to monitor weight gain, process gestures, make phone calls, and many more. Company Athos has plans as well to release fitness clothing that measures heart rate, muscle activity, and respiration in real time.
Echo Labs researchers are also currently producing a biometric band that can track oxygen, carbon dioxide, PH level, hydration, and blood pressure through optical signals.
Implantable technologies are also underway, with digital tattoos and internal microchips potentially replacing the smart wristbands and similar devices of today.
It may not be all bright and rosy, though, as this technology could have a dark side to it.
In a survey involving 200 women using Fitbit, the device's role in daily life was established: 79 percent felt they were under pressure to reach daily targets, 59 percent had daily routines controlled by Fitbit and 77 percent would return home to get their Fitbit if they left without it.
"Whether we want to or not, we are slowly, but steadily, transforming into a new human species. Enter: homo cyberneticus," said the analysis.
Photo: Kārlis Dambrāns | Flickr