Smartwatch accuracy tester Rob ter Horst uses a paper which was partly funded by Polar as a scientific justification for the choice of the Polar H10 as his reference device for his scientific tests: RR interval signal quality of a heart rate monitor and an ECG Holter at rest and during exercise https://pubmed.ncbi.nlm.nih.gov/31004219/#full-view-affiliation-1 The paper …