Last Updated on January 13, 2026 by pg@petergamma.org
DC Rainmaker and 5k runner regularly made statements for instance about the accuracy of the Polar OH1 optical heart rate monitor. They clamed that the Polar OH1 is very accurate if not the most accurate optical heart rate monitor. These statements cached the interest of Peter Gamma, Director of the Meditation Research Institute Switzerland (MRIS). And Peter wanted to know, how accurate are those? Are there no scientific studies about it?
Yes, there are. But none of these used the same testing protocol. So data from one paper could not be compared to a study in another paper:
Was this done on purpose? And where these promo papers on request of sellers? Peter Gamma from www.petergamma.org continued to be interested in scientific studies about smartwatches. And that is when Rob ter Horst came onto the market:
And when Rob started his tests, Peter s first thought was:
„ Is this man joking?“
But Rob did not stop. So Peter compared the papers one to another in more detail:
And after that, Peter s interest in using smartwatches of scientific studies came to an end.
But Rob ter Horst kept on testing smartwatches scientifically. And there is where Peter s interest in Rob ter Horst came to an end.