The validity of OH1's heart rate measurement has been studied in several papers successfully. For example, the mean absolute error at rest and during various physical activities was 0.4% ranging from 0.1-0.9% in comparison to Polar H10 (Gilgen-Ammann). A high level of agreement with the criterion measure ECG was also achieved in walking and cycling activities (Hettiarachchi), and with the Polar H7 as a reference method in various endurance sports and soccer (Hermand). According to the researchers Polar OH1 provides the best wearing comfort and very precise optical HR measurements at rest and during different exercise modes.
Hettiarachchi IT et al.”Validation of Polar OH1 optical heart rate sensor for moderate and high intensity physical activities.”, PLOS ONE https:doi.org/10.1371/journal.pone.0217288 May 23, 2019.
Hermand E. et al. ”Validation of a Photoplethysmographic Heart Rate Monitor:Polar OH1”. Int J Sports Med 2019;40:462-467. DOI https://doi.org/10.1055/a-0875-4033.
Gilgen-Ammann R. et al. Accuracy of the optical heart rate monitor Polar OH1 at rest and during exercise. Abstract (24-1449) and e-poster. ECSS annual meeting, Prague, Czech Republic, July 3-7, 2019.