Did a 1K time trial today on a path. Started under a bridge. My fitness is improving (masters runner) and felt like I was running faster than ever and managing to hold my pace, so wasn't too surprised when my Garmin said 3:30, which is an improvement of over 15 seconds for me. Looked at Strava on the phone and the pace looked normal on the phone. Then when I got home and looked again on my laptop, there is clearly a GPS fail for the first 150m or so, with me going at 1:50 km/m which is obviously ridiculous. So do I take off 10 or so seconds from my time, or does Strava 'balance it out', so the 3:30 time is still accurate? My Garmin says 3:35, although it also says a new 1K pb of 3:30.