Most people using a treadmill at the local gym can’t use a Runn device for various reasons.
For someone like myself who uses a local gym, the best way to track running is by using a foot pod.
From my understanding, the best foot pod available is the Stryd.
It would be great if Technogym treadmills had Bluetooth functionality that worked with Zwift and could link to Zwift for speed tracking, but unfortunately, they don’t.