How accurate are the heart rate monitors on both watches during intense workouts

General Accuracy Trends

1. Performance During Intense Exercise
- Studies indicate that wrist-worn heart rate monitors, including those in both watches, tend to be less accurate during high-intensity workouts. As exercise intensity increases, these devices often underestimate heart rates. For example, a comparative study found that wrist devices generally have lower accuracy at higher exertion levels, particularly above 150 beats per minute (bpm) [1][3].

2. Specific Device Insights
- The Galaxy Watch 7 has been reported to provide reasonably accurate readings during moderate exercise but shows diminished accuracy during high-intensity activities. It may struggle to keep up with rapid changes in heart rate due to its optical sensor technology [1][5].
- The Pixel Watch 3, benefiting from Fitbit's advanced algorithms, has shown improvements in heart rate tracking accuracy during intense workouts compared to previous models. However, it still faces challenges similar to other wrist-based monitors when subjected to high-intensity intervals [1][2].

Factors Influencing Accuracy

1. Sensor Technology
- Both watches use photoplethysmography (PPG) to measure heart rate, which can be influenced by factors like skin tone, movement, and how tightly the watch is worn. Tighter fitting can enhance accuracy by ensuring better contact with the skin [5].

2. Activity Type
- Accuracy may differ across various types of workouts. For instance, steady-state aerobic exercises like cycling tend to yield more accurate readings than activities with rapid heart rate fluctuations, such as HIIT or circuit training [1][3].

3. User Experience
- Users have reported that both watches can lag in heart rate reporting during intense workouts. For example, the Galaxy Watch 7 might show a delay in reflecting actual heart rate changes during high-intensity sprints or intervals [2][4].

Conclusion

In summary, while both the Pixel Watch 3 and Galaxy Watch 7 offer heart rate monitoring capabilities suitable for fitness tracking, their accuracy diminishes during intense workouts. The Pixel Watch 3 may provide slightly better performance due to its enhanced algorithms but still encounters limitations typical of wrist-based monitors. Users looking for precise heart rate data during high-intensity exercise may benefit from considering chest strap monitors for improved reliability.