Fitness trackers are everywhere these days on iPhones and watches. Fitness enthusiasts and those trying to achieve their goals use these trackers to count steps, track workouts, and measure calories. With so many people depending on them for reliable data, it raises the question: How accurate are those wearables? Are we really getting the correct data on our calories, heart rates, step counts, and more?
In a study published in the European Journal of Applied Physiology, the researchers note that wearable technology has been named the number one most popular trend, and this popularity is predicted to continue growing. Despite their merits and benefits, the researchers also highlight the significant limitations associated with the validity and reliability of the metrics measured from these devices. As they rightly say, advanced marketing doesn’t always equate to advanced technology.
Recently, a professor and doctoral student at the University of Mississippi set out to explore the accuracy of these wearables. Here’s the scoop.
New research
In the new meta-analysis, researchers reviewed 56 studies that compared the popular Apple Watch to standard, trusted measuring tools for heart rate, step counts, and calories burned. They presented their study at the University’s Showcase of Research and Scholarly Activity session.
For this analysis, the researchers assessed the accuracy of the Apple Watch across different age groups, health statuses, and types of physical activity. They also tested various versions of the device.
The researchers raised concerns because some people are using these devices to help guide decisions about their medical conditions or workouts, so it’s important that the data is accurate. Otherwise, inaccuracy could cause confusion, overtraining, or even cause some people to miss health warnings.
The results
The results of this meta-analysis reveal that, overall, Apple Watches are accurate for measuring step counts and heart rate. The MAPE or mean absolute percentage error is a standard statistical measure that helps determine the accuracy of forecasts and predictions compared to actual values. Researchers calculated the difference between the data from the Apple Watches and the data from standard trusted measuring tools before calculating a “percentage error.”
Here are the MAPE results:
- 4.43% for heart rate
- 8.17% for step counts
- For energy expenditure, the error increased to 27.96%, showing a more significant inaccuracy.
The researchers found this inaccuracy with all individuals and activities, including cycling, running, and walking.
The takeaway
The takeaway is that while Apple Watches and similar devices can be useful tools in your fitness toolkit, they shouldn’t be considered a replacement for sound medical judgment or advice and standard clinical measuring tools and technology. It seems that, particularly with values like energy expenditure or calories, Apple Watches might not provide the most reliable data. These nifty little devices appear to be better at collecting certain types of data compared to others. As we can see in this analysis, the MAPE for heart rate was only 4.43%.
That being said, big companies like Apple are refining and improving their technology, which will hopefully enhance accuracy in the future for those of us who want to use fitness trackers.
