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

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Sports Science

Background:

• Photoplethysmography (PPG) smartwatches are common for continuous heart rate (HR) monitoring.
• Accuracy is established for resting and low-intensity activities, but data during maximal exercise are limited.
• Validation is crucial for PPG devices in demanding conditions like clinical exercise testing and athletic training.

Purpose of the Study:

• To assess the validity of the Samsung Galaxy Watch 6 (GW6) for estimating HR during maximal treadmill exercise.
• To investigate if measurement error differs across five predefined HR intensity zones.

Main Methods:

• 55 healthy adults underwent a maximal ramp cardiopulmonary exercise test on a treadmill.
• Simultaneous HR data were collected using the GW6 and a Polar H10 chest strap (reference).
• Agreement indices (ICC, errors) and Bland-Altman analysis were computed across HR intensity zones.

Main Results:

• Agreement between GW6 and Polar H10 varied by intensity, with good-to-excellent ICC (0.90) at 90%-100% HRmax.
• Median absolute error was consistently low (1-3 bpm), and percentage error decreased with intensity.
• GW6 showed a mean bias of -2.67 bpm, underestimating HR, with wide limits of agreement, indicating individual variability.

Conclusions:

• The GW6 demonstrates good validity for HR monitoring during maximal treadmill exercise in healthy young adults.
• Despite minor error increases at high workloads, absolute errors are clinically acceptable.
• The GW6 shows potential as a convenient, noninvasive HR monitoring alternative for laboratory exercise testing.