The Edit Runs window allows you to change the name or default distance of a run or inactivate a run so that it doesn't show up in the Run Entry window.

You can also add new runs from here by simply clicking the New... button. You don't have to enter runs from here because, runs are added automatically each time you type a new run name in the Run Entry window. To edit a run, simply click the Edit... button and edit using the Edit Run window (below):