Battery dies during workout, how to complete the track?

When skiing cross country I sometimes find the battery die during the workout in the middle of a track. 

i have edited the record by saving the track as a course and Looping to Start to get the distance right and elapsed time right, but the record itself cannot be edited, except for the alpha-numerics. 

Has any of them developers figured a worksround to edit the actual track, which was synced from the watch?