bieżnia mechaniczna in English:

I hate this treadmill of working in my office

Sometimes I just want to get off this treadmill and go live in the countryside.

I run on the treadmill every day.

I run on the treadmill every day. I can't seem to change the speed of the treadmill.

We need you to walk on this treadmill

With half an hour on this treadmill you'll work up a pretty good sweat.