How accurate is the Apple Watch's step and distance meter?

How accurate is the Apple Watch's step and distance meter?

What motivates a person to buy a Apple Watch? This is a difficult question to answer, but without a doubt the monitoring of the watch's physical activities is one of its great commercial pillars. We have already seen here on the website that the heart rate sensor is very accurate (despite having an annoying bug in Watch OS 1.0.1). But what about the step / distance meter? Can we trust him? Dan Graziano, from CNET, decided to get it out.

It is worth noting that steps and distance traveled are two metrics that are related, but totally independent. Two people can walk the same distance in the same period, but with a number of different steps the height of a person, for example, can influence a lot in this since the greater the height, the greater the amplitude of the step. Not to mention, of course, that "walked" steps are quite different from "run" steps.

Calibrating your Apple Watch

When you open the Exercise app (Workout) for the first time, the watch asks you to walk 20 minutes outdoors with your iPhone. In addition, it is important to set the date of birth, gender, height and weight information in the Apple Watch app (tab My Sade Watch), since they are important information and must be taken into account.

Health data on your Apple Watch

But why is the 20-minute walk with your iPhone important? For one simple factor: these 20 minutes will define a distance and the number of steps you took to reach it. Using the iPhone's GPS, this distance is plotted with great precision. Thus, Watch will know exactly your average steps to reach that certain distance, making life easier when you walk or run without the iPhone nearby.

Graziano took the Watch and other smart watches / bracelets from the market and walked, on a treadmill, 1 mile (1.6 kilometers) at a speed of 3.5 miles per hour (5.6 kilometers per hour), totaling about 17 minutes walk. This is using one device at a time, repeating the test three times. He left some familiar devices (such as the UP MOVE, the various models of the UP bracelets and some other Android watches) out of the tests as they simply do not show the information in real time, making it difficult to measure the distance traveled during the test.

The result you can see below:

Comparative table - Steps and distance

The calibrated Apple Watch was the one that got the best performance, with a margin of error of just 0.3%. It is worth noting that, uncalibrated, the clock was one of the worst (10% variation). For Graziano, the Moto 360 was the most inconsistent of all devices, as it showed very high numbers of steps in the three tests (giving an average of 2,190, the highest among all watches / bracelets without counting the final distance, which also varied a lot and ended up being the smallest).

Of course, for a person's day-to-day life, this test may not represent anything, after all, these devices can confuse activities like washing dishes or lifting weights like steps, since they usually measure the balance of the arm to calculate everything. That is, a device can be great at monitoring an activity, but it can also count things that are not exercises as being and disrupt all of their monitoring.

Still, it is interesting to see that Apple got it right (when the Watch is calibrated) already in the first generation of its watch.