1. Pull a patch panel from outside the room, connect it to the running machine, and then turn it on to see if it will affect the network.

2. Move the treadmill out of the room and try it in a far place to see if it is feasible.

3. Try to keep the dialer or router away from the treadmill.

If the above method is used, the network will be affected. Need to find a professional electrical appliance or consult a network provider. Because treadmills belong to electrical appliances. There are motors and magnetic fields inside. Maybe your network cable is close to the wire of the socket, and there is signal interference inside.