You can create a Variable Speed effect that is automatically sized to fit a marked IN to OUT duration in a sequence by clicking the Fit to Fill button.

The Fit to Fill button is located on the Edit tab of the Command palette. This button performs an overwrite edit and uses a motion effect to fill the marked duration in the Timeline. When you click the Fit to Fill button, the Avid editing application automatically creates a motion effect using the clip in the Source monitor. The application selects variable-speed parameters so that the duration of the motion effect matches the IN to OUT duration marked in the Timeline. The application then overwrites the motion effect into the sequence.

The motion effect you create with the Fit to Fill button uses the parameters you set in the Render Settings and Media Creation dialog boxes. If the Render preference is set to Original Preference, the new motion effect is rendered with duplicated fields.

To create similar effects, see the following: