Validation of heart rate measurements from the polar verity sense during the submaximal Ekblom-Bak test in adult individuals with obesity.

Participants were a convenience sample from one inpatient obesity rehabilitation programme, and no a priori sample size calculation was done for the validation analysis. The criterion device was the Polar H10 chest strap, not an ECG, because ECG recording was not available at the facility. The test only examined steady-state cycling at low and higher work rates, so the results do not show how the device performs during fluctuating intensity or other activities. Estimated VO2 max agreement was not an independent validation of VO2 max, because VO2 max was calculated from heart rate. Participants who had previously done the test kept their earlier workload, which reduced individualization and was reflected in one participant being unable to complete the test. The questionnaire responses were analysed descriptively, so preference and discomfort findings are participant-reported experiences rather than statistically analysed differences. The upper-arm device had a single size, and 2 participants reported discomfort from tightness despite maximum strap length. The validity analyses used one averaged heart rate value per participant at each work rate, so the number of paired comparisons was lower than the total number of second-by-second heart rate recordings.

The authors declared no conflicts of interest. The study was internally funded by NTNU.

Do not conclude that the Verity Sense independently measures VO2 max, works during fluctuating exercise, or applies outside adults with obesity in this cycle test. The study tested steady-state cycling only, and VO2 max estimates were calculated from heart rate rather than measured directly.