Time Out has a handy feature to automatically skip breaks when specified apps are frontmost or running.

This works with most apps, including the Zoom teleconferencing app. However, if you find that it sometimes doesn't work, it is probably using an internal helper tool during a call, e.g. for screen sharing.

There's a solution, however. Follow these steps to stop breaks occurring during meetings:

1. Locate the Zoom.us app in the Finder.
2. Right-click it and choose Show Package Contents.
3. Navigate into the Contents ▸ Frameworks subfolder, and find the Transcode app.
4. Go to Time Out's Exclusions page.
5. Click the + button to display the choose panel.
6. Drag the Transcode app into the panel, and click Choose.

You should add both the main app and the helper one, and will probably want to set both to Skip When Open.