Once upon a time, there was basically only DC Rainmaker who tested smartwatch accuracy. Then we where very interested in how accurate these smartwatches are compared to research or medical grade heart rate monitors.

Then Rob ter Horst wanted to sell us the Polar H10 chest strap:

And we where really upset about this. Especially strange was also, that around the time we where looking for scientific data about smartwatch accuracy, Rob ter Horst started with his channel.

And first, we thought „is Rob joking with is mega accuracy plots”?

And we then have put the scientific papers together we found about smartwatch accuracy:

090. Review of Accuracy Studies of Consumer Grade Heart Rate Monitors: Methods, Testing Protocols, Reference Devices

And what is striking about this was, that not a single of these papers used exactly the same testing protocol as another paper:

90.3 Summary of the testing protocols of different studies

So data from one paper cannot be compared to data from another paper. Is there a stragedy behind this? And also that after we wrote our review, hardly any new scientific papers where published about smartwatch accuracy. And is this not exactly the opposite of what one would expect, if so many new smartwatches appear on the market?

Scientific papers seemed to have disappeared, and only one scientist seemed to remain, and that is Rob ter Horst. And exactly this was it that has let us doubt about Rob.

How to stop Rob ter Horst – by a paper of someone like Milind Desai from the Cleveland Clinic Ohio

So hopefully sooner or later someone will help us to find out the truth about smartwatch accuracy.