Apple’s Latest Heart Rate Sensor Matches Industry Leaders, But Lacks Clear Edge
With its latest heart rate tracking accuracy improvements, the Apple Watch Series 12 now rivals top models like Garmin’s Forerunner 570. Despite Apple’s assertion that this updated sensor delivers the “most accurate heart rate in a wearable,” side-by-side evaluations highlight a more complex picture.
Bold Assertions and the Progression of Apple’s Heart Rate Sensors
According to Apple, both Series 12 and Ultra 4 Apple Watches are equipped with the most advanced heart rate sensors in today’s wearables, featuring a hardware update that includes larger, tightly grouped circular LEDs. To back up this claim, Apple published the Heart Rate Accuracy Study 2026, showing results from comparisons with seven modern devices over multiple activities. Although the report supports Apple’s claims of leadership, only high-level findings were shared, leaving the extent and openness of this evidence up for debate.
Earlier Apple Watch generations, including the Series 4, generally surpassed other wearables in terms of optical heart rate sensor reliability at launch, but more recent entries from Garmin and Google’s Pixel Watch have taken the accuracy lead. Fitness communities and reviewers frequently placed Garmin’s Forerunner 570 as the benchmark, while Apple’s Series 10 and 11 sat just below in the rankings.
Real-Life Comparisons: Series 12 Faces Garmin Forerunner 570
The performance of Apple’s newest model was evaluated through side-by-side field tests against the Garmin Forerunner 570. Devices were worn on separate wrists, and an industry-standard electrical chest strap provided a control for accurate heart rate data. Four types of workouts were used: treadmill running, trail running outdoors, rowing machine sessions, and weight training exercises.
Testers minimized interference from skin tone, wrist size, and device placement by ensuring snug fits on untattooed, hair-free six-inch wrists. To push both devices, routines included a mix of steady-state exercise, interval surges, and gym activities, all under variable conditions of light and temperature.
Analysis showed that both Apple and Garmin watches usually stayed close to the chest strap’s readings, but unique device behaviors emerged. The Forerunner 570 sometimes trailed behind at the start of intense activity, then quickly adjusted. Conversely, the Apple Watch occasionally missed recording peak heart rates or had gaps at the session’s beginning.
During rowing sessions, the Garmin sometimes missed nearly 50% of the second interval, failing to fully track sustained efforts, while the Apple Watch was prone to overshooting heart rate or missing rapid drops. Both watches demonstrated weaknesses in weightlifting: Garmin’s values were often too low, whereas Apple’s readings alternated between overestimates and unexplained omissions.
Assessing Apple’s Accuracy Advantage
The Series 12 Apple Watch has delivered major gains over its predecessors, equaling the Forerunner 570’s performance in the majority of normal workout scenarios. Notably, Apple’s device only reports a heart rate if it has high confidence in its precision. This strategy reduces the chance of inaccuracy, though it sometimes results in missing segments where no data appears—unlike Garmin, which offers a constant data stream but can be less precise at times.
These differences complicate Apple’s “most accurate in a wearable” claim. The Series 12 often prefers omitting uncertain values, avoiding incorrect reports, while Garmin’s continual data can be both helpful and misleading. Overall, both models occupy the top tier of wrist-based monitors, without one showing undeniable superiority in every circumstance or activity.
Importantly, chest-strap sensors still maintain their status as the most precise option compared to wrist-worn optical devices. This distinction remains, even with the latest advancements.
Conclusion
The heart rate sensing capabilities of the Series 12 Apple Watch mark a strong upgrade, meeting the accuracy levels achieved by leading Garmin products. While the new Apple Watch matches A-tier accuracy, direct observations demonstrate that neither it nor Garmin can claim unmatched performance across all uses. For the highest standards of accuracy, chest-strap monitors are still the preferred choice. Nonetheless, Apple’s redesign proves to be a significant improvement, making the Series 12 a highly trustworthy option for heart rate tracking throughout a variety of fitness routines.