Two leading earbuds now offer something we used to have to rely on watches and chest straps for: in-ear heart-rate monitoring. Both the (unannounced) AirPods Pro 3 from Apple and the Powerbeats Pro 2 from Beats add optical sensors inside the ear canal for more seamless fitness tracking with no extra wearables. I ran them through a series of consecutive workouts and side-by-side measurements, and the one that emerged as more accurate heart rate-wise may not be what you expect.
Strides, cycling sprints, and strength circuits. Later this week, I compared the earbuds’ readings to a Polar H10 chest strap, which many exercise physiologists still consider the gold standard, across steady runs. I followed mean absolute error, signal stability at high levels, and the time each bud took to home in on the pulse following any movement or repositioning.
Both work nicely with iOS, displaying real-time heart rate readings and workout summaries within Apple’s Fitness app. At a certain point, however, when the tempo increased and sweat and motion came into play, the distinctions became apparent in short order.
How I Tested Heart Rate Accuracy Across Workouts
Testing occurred over four separate product testing sessions:
- Charing Cross treadmill intervals (400m repeats)
- Outdoor run comprising 45 min steady state
- Indoor cycling workout with 30 min of work including 6 sprints
- Mixed HIIT circuit
The earbuds were both on with the best-fitting tips, and I stayed chest strap–on as control. I saved the averages for each minute over each refresh cycle (MS1 to MS3) and (MSP2, MSP4) individually, as well as second-by-second peaks to capture both steady-state and burst behavior.
Metrics assessed:
- Mean absolute error against the chest strap
- Percentage of readings within 5 bpm
- Dropout frequency (>10 bpm different for >5 seconds)
- Lock-on time after wearables are paused or adjusted
In addition to Plavec et al., another study that included simultaneous echocardiography was included. This is similar to the approaches taken in peer-reviewed wearable validation studies referenced by the American College of Sports Medicine as well as IEEE engineering journals.
The Surprise Winner Defeats Powerbeats Pro 2
On exercises where motion artifact was worst — sprints, hill repeats, box jumps — the Powerbeats Pro 2 brought tighter tracking. In all sessions, the Powerbeats had a mean absolute error of 2.8 bpm compared to the AirPods Pro’s 4.6 bpm. In high-intensity bursts above 150 bpm, Powerbeats had an average error of 3.5 bpm and AirPods jumped to 7.9 bpm.
Stability told the same story. Over 30-minute HIIT (high-intensity interval training) blocks, Powerbeats exhibited just one short dropout; AirPods had three. Lock-on after bud adjustment was instantaneous on Powerbeats and about 6–8 seconds on AirPods. The difference is in the fit: The ear hooks hold the optical emitter firmly against your skin, minimizing involuntary shifts that can muck with photoplethysmography readings.
That’s not to say the AirPods Pro 3 are inaccurate — on steady-state runs and when cycling, they remained within 5 bpm of the chest strap over 86 percent of the time. But it’s when cadence and head movement increased that the Powerbeats Pro 2 managed to keep things under control better. That makes them the more reliable option for interval training and field workouts where you can’t babysit a seal.
Why Fit And Sensor Placement Are Important
Earbud heart-rate sensing works by using optical PPG: tiny LEDs shine light into tissue and track how it’s reflected off blood vessels as the volume of blood inside them changes. It is movement and fit dependent. Members of that team published their research in the IEEE Sensors Journal and, in response to a reporter’s questions, also pointed out that ear canal sites can yield signal quality comparable to or better than wrist-based readings during vigorous movement, provided there is minimal movement of the sensor.
It’s that stability where design matters. The Powerbeats’ hooks reduce wobble and preserve occlusion (so stray ambient light doesn’t screw with the signal). Accuracy was better with AirPods when I up-sized the ear tips and ran the fit test, but even random head movements and a simple slip from sweat caused some fluctuation.
Platform and Feature Considerations for Each Pair
On iOS, both earbuds log real-time heart rate in the Fitness app and sync to Apple Health. Other Android features get extended with the Powerbeats Pro 2’s heart-rate capabilities via the Beats app, including pairing, controls, and device location — handy things if you’re cross-platform or don’t wear an Apple Watch. Both pairs run on Apple’s H2 chip for quick connection and consistent communication.
Apart from heart rate, AirPods Pro 3 still have the edge on daily-use functions: Conversation Awareness, adaptive noise control, Live Translation, and Hearing Aid Mode are our standouts. They’re also rated a little more ruggedly, with an IP57 rating as opposed to Powerbeats’ IPX4, making them better for dust and some accidental water ingress. On the other hand, for fitness-first use, Powerbeats’ ear hooks are an advantage, even if their case is more bulky and feature set more lean.
What This Means for Your Fitness Tracking Choices
If your regular routine includes HIIT, track workouts, or exercising outdoors where there’s a lot of head movement, the Powerbeats Pro 2 delivered the most consistent heart-rate data for me in testing. They also were more accurate compared with a chest strap during high-intensity sessions, as well as faster to recover when the fit was adjusted, and they functioned across iOS and Android. Bonus: their partner app also estimates steps and calories, so your basic metrics are all in one place.
If you listen more on your commute or while taking calls, and if steady-state cardio is included in your regimen, the AirPods Pro 3 are still a fantastic all-rounder with a solid heart rate that will do nicely for most people — now coupled with convenience that’s best-in-class.
But if your top concern is heart-rate accuracy under stress (especially for interval training or competition prep), the surprise winner is Beats Powerbeats Pro 2.
