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Accepted for/Published in: JMIR Cardio

Date Submitted: Aug 7, 2025
Date Accepted: Feb 10, 2026

The final, peer-reviewed published version of this preprint can be found here:

Heart Rate Estimation Using the Galaxy Watch During Maximal Cardiopulmonary Exercise Testing: Cross-Sectional Validation Study

Rodrigues AI, Soares JPF, Antunes-Santos F, Ferreira ARP, Gonçalves AdAC, De Lima JAA, dos Santos MR

Heart Rate Estimation Using the Galaxy Watch During Maximal Cardiopulmonary Exercise Testing: Cross-Sectional Validation Study

JMIR Cardio 2026;10:e81917

DOI: 10.2196/81917

PMID: 15608475

PMCID: 13086260

Warning: This is an author submission that is not peer-reviewed or edited. Preprints - unless they show as "accepted" - should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.

Validity of Galaxy Watch for estimating heart rate during maximal cardiopulmonary exercise testing

  • Allan Inoue Rodrigues; 
  • João Paulo Ferreira Soares; 
  • Felipe Antunes-Santos; 
  • Alexandre Reis Pires Ferreira; 
  • Alberto de Almeida Campos Gonçalves; 
  • João Arthur Alcântara De Lima; 
  • Marcelo Rodrigues dos Santos

ABSTRACT

Background:

Smartwatches have become popular for monitoring various health parameters, including heart rate (HR). In some smartwatches, the HR is estimated using photoplethysmography (PPG) sensors. There is limited literature demonstrating the validity of PPG-based HR monitoring smartwatches in estimating HR during maximal exercises.

Objective:

We aim to determine the validity of Galaxy Watch 6 (GW6) devices in estimating HR during a maximal ramp cardiopulmonary exercise test (CPET) conducted on a treadmill with fifty-five healthy participants.

Methods:

We selected a Polar H10 device as the golden standard and evaluated HR across five intensity zones: 50–60%, 60–70%, 70–80%, 80–90%, and 90–100% of the participant maximal HR (HRmax). HR data from the GW6 and Polar H10 were compared using the intraclass correlation coefficient (ICC), the typical error of measurement (TEM), and the mean absolute percentage error (MAPE).

Results:

The TEM% ranged from 2.9 to 4.2%. The MAPE, ranged from 1.9 to 3.7%. The smallest systematic difference was observed for the highest intensity zone (90-100% HRmax).

Conclusions:

The GW6 PPG-based technology demonstrated reasonable validity in monitoring HR during CPET tests.


 Citation

Please cite as:

Rodrigues AI, Soares JPF, Antunes-Santos F, Ferreira ARP, Gonçalves AdAC, De Lima JAA, dos Santos MR

Heart Rate Estimation Using the Galaxy Watch During Maximal Cardiopulmonary Exercise Testing: Cross-Sectional Validation Study

JMIR Cardio 2026;10:e81917

DOI: 10.2196/81917

PMID: 15608475

PMCID: 13086260

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