So, I moved the visible area in those frames to include the action. When I set my project to Crop, many of the portrait photos ended up showing just sky. Or, feel free to adjust any of the frames manually. You can then click the Fit or Crop button that appears in the Viewer. If you want to change whether the photos are cropped or set to fit within the frame, select all frames (click one and then choose Edit -> Select All, or press Command-A) and then click the Crop button on the toolbar.