Open a video in the Analyze workspace

Click on the drawing tools and select the measuring tool

First add a reference measure equal to one meter on the video

Once the reference is defined, use again the drawing tool to measure distances

Be careful to define precisely the reference as all the following measurements will be calculated based on it.

This measure drawing tool can calculate distances in the same 2D plane that the reference. The depth is not accounted for (e.g. in the above example it is not possible to calculate the distance between athlete and the back wall).