Which problems do you encounter with these two metrics?

I can’t access these metrics via the api. I don’t get any data back.

Relative effort (subscribers only):

Endpoints: /activities/{id} or /athlete/activities

Key: suffer_score

Private notes:

Endpoint: /activities/{id}

Key: private_note

My suggestion would be to dump the raw JSON output from getActivityById and browse through the fields. You can either use something like Postman to view it, or just dump the output to a log file in your app. You'll see the field names and values which should help you figure out exactly how to extract the data you're looking for, what it looks like, and whether it's available at all 

Thanks both,

it works now with the correct properties Jan posted.

many thanks