GPSFunRunner 3D is a third party application which allows the comparison of two separate .tcx files within 3Dimensions
The initial interface menu allows you to view what two files will be imported into the GPSRunner application for comparison in 3Dimensions.
The main program shows the training data in 3Dimensions with the height of the pillars on the route being representative of the speed at the recorded time.
The Demonstration version allows you to import two of your own tcx files. The following image shows typically where you import the files from in Windows Explorer.
The Full Version is expected to be released later in 2017.