Heartrate stream missing from Strava API despite athlete using a heart-rate monitor

Hello everyone,

I'm developing a university project in Python using the Strava API directly through requests.

For some activities, the request to GET /api/v3/activities/{activity_id}/streams returns HTTP 200, but the heartrate stream is missing.

For one affected activity, the results are:

• has_heartrate: false

• average_heartrate: null

• Requested stream: heartrate

• Returned streams: distance

The athlete has confirmed that they used a heart-rate monitor during the activity. Our OAuth authorization requests the activity:read_all scope, and token refresh works correctly.

Other activities from other athletes do return heart-rate data through the same code.

My questions are:

1. Can the heart-rate stream be unavailable through the API even when an athlete used a heart-rate monitor?

2. Does has_heartrate: false mean that Strava has no heart-rate data available for that activity, or could this indicate an API access issue?

3. Are there any additional permissions or conditions that could explain this behavior?

I can provide sanitized API responses and further details if needed.

Thank you!