According to a new study that was just published yesterday in the Journal of Personalized Medicine, popular fitness trackers are not reliable when it comes to calorie tracking, but they are effective at monitoring heart rate.
“We were pleasantly surprised with how well the heart rate did,” said Euan Ashley, professor of cardiovascular medicine at Stanford University and co-author of the report. “Under many scenarios, for most of the devices, they actually did really fairly well,” he said.
“At the same time, we were taken aback by how inaccurate the calorie estimations were for the tools; they were all over the place,” we said. “This did not bode well for us.”
For the purpose of the study, the research team, composed of members from Stanford University and the Swedish School of Sport and Health Sciences, selected 31 female participants and 29 male participants. Although the sample size was somewhat low, the researchers ensured that there was a wide range of ages, sizes, and weights within the group so that the results would be more representative of the overall population. A total of seven different fitness trackers, including the Fitbit Surge, Apple Watch, Mio Alpha 2, PulseOn, Microsoft Band, Samsung Gear S2, and Basis Peak, were put through their paces during the evaluation process.
While walking or running on treadmills or on stationary bicycles, volunteers wore anywhere from one to four fitness trackers at the same time. The data was then analyzed using the electrocardiograph (ECG) and indirect calorimetry, two of the most accurate methods for determining heart rate and calorie consumption, respectively.
The Journal of Personalized Medicine is the cited publication.
According to the findings of the study, wearables have a good degree of accuracy when it comes to detecting heart rate. Six of the seven devices generated readings of the heart rate with a median error of about 5 percent, which is an extremely accurate reading. The scientists considered anything less than 10 percent to be an “acceptable” level of risk. The Apple Watch came out on top with an error rate of only 2 percent, while the Samsung Gear 2 fared the worst, citing an error rate of 6.8 percent.
Even if it is obvious that the methods used to measure heart rate have been more accurate over the years, it is important to stress that you should still exercise caution, particularly when it comes to physically demanding activities. This is due to the fact that inaccurate readings can be hazardous, even if they only occur occasionally. This is because they can lead individuals to overexert themselves because they mistakenly believe that their pulse rate is normal while in fact it is abnormal.
However, this is where the good news comes to an end. When it came to the number of calories burned, the results were all over the place. The Fitbit Surge, which is widely regarded as the most accurate device, has an error rate of about 30%. was actually fairly good in comparison to the Pulse On fitness tracker, which was off by an astounding 93% of the time! The fact that the results are inaccurate by a significant percentage places them squarely in the realm of fiction rather than actuality. Once more, anything less than 10 percent was considered to be within the allowed range of variation. There was not a single device that passed the test that was successful.
Anna Scherbina, who was the primary author of the study, stated that “the mistake depends on the type of activity you’re recording.”
“The results are more accurate for activities like walking and sitting than they are for more vigorous pastimes like spinning and running,” she continues. “These activities include strolling.” The main idea is that you are not expanding as much energy as you believe you are.
It seems that the takeaway here is that we can now rely on the heart rate measures provided by fitness trackers to a far greater extent than in the past. But chowing down on a couple of donuts because the fitness tracker on your wrist tells you that you burned 700 calories during the spin class? Probably not the wisest course of action.