I've been running a lot recently with my partner as part of a new year's health kick. I run with a Garmin Instinct Solar whereas she just tracks using the Strava app on her iPhone. We come out with different results every time and, whilst I would expect my watch to be more accurate than the standard iPhone GPS, I'm not always 100% convinced based on the map etc.

Whilst the differences in timing etc do not make much of a difference to me as I am not a serious runner, she has targets in mind as she is training for a half marathon later this year and feels it might be hampering her as she is worried she will not be running at the required pace for her target time based on her training.

What do you think we should do to judge the most accurate stats for our runs?