Is there an answer to this already? I also miss the possibility to select which activities contribute to the reports. E.g. if I do trail running, stair climbing and "normal" running, the results are all melted into one unuseful average. Monitoring progress is killed by this simple thing.
You can run separate reports for Running, Swimming, and Biking, so nobody forces you to use the total values for all disciplines merged.
And if you want reports filtered even finer than just by the category - for example when you want to see totals separately for Trail Running and Street Running, or Track Running, just use the Progress Summary page, where in the last dropdown box, you can select the desired sub-category. On the extreme right, you can then use the Customize option for adding/removing the fields of the report.