Can an iPhone app receive AirPods Pro 3 heart-rate updates once per second through a supported API?

App & System Services Health & Fitness
NoCarrier OP
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I’m building an iPhone app that aligns live heart-rate readings with a video recording. I’m looking for a supported way to receive a fresh AirPods Pro 3 BPM estimate about once per second during an active session.

I tested with an iPhone 16 running iOS 27.2 and AirPods Pro 3. A minimal test app starts an HKWorkoutSession on the iPhone, collects heart rate with HKLiveWorkoutBuilder, and records the source timestamp of each distinct reading. With both .other / .indoor and .running / .outdoor, the median spacing between readings was about five seconds. Querying HealthKit afterward returned the same in-take readings.

Is that cadence expected for third-party apps? Is there a documented API, workout configuration, or capability that Apple makes available to third-party developers for receiving fresh AirPods Pro 3 BPM estimates at about 1 Hz?

My requirement is for a new estimate from the AirPods at that cadence. Polling more frequently or interpolating between readings would not meet it.

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DTS Engineer OP
Apple

When an active HKWorkoutSession is running, the system already measures the heart rate at a high frequency. There is currently no API that can have the frequency go even higher.

With the latest system and devices, you can expect that the heart rate measurement happens every five seconds, as mentioned here.

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.
NoCarrier OP

Thanks for the clarification. The linked announcement describes passive Apple Watch sampling.

Is there any supported way for a third-party iPhone app to receive a new AirPods Pro 3 BPM estimate roughly once per second, either through HealthKit or through another API or capability available to developers?

DTS Engineer OP
Apple

There isn't. AirPods Pro 3 samples the raw data points at a highly intensive rate, but the system calculates the heart rate (using the raw data points) and puts the result into the HealthKit store at a much lower rate. In the latest system, that's roughly 5hz. The mechanism applies to Apple Watch as well, and that's why I mentioned the linked announcement.

Other than HealthKit, the system doesn't provide any other API to access the heart rate data from AirPods Pro 3 or Apple Watch.

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.