Basically there are more reason why you didnt get track recoded.
1) Before start be sure that you gps localize your position (move a little bit around the place)
2) You location service is switched off
3) You set in your configuration Gps accuracy to the maximum, in this case you have to be sure no obstacles around you.
4) you are in a city and the gps signal is weak or unavailable
5) In some situation is best also to switch off the feature GPS ACCURACY
We suggest to manage a little bit with settings of the gps inside the app to find the best app tuning.