We sometimes receive questions regarding data change after syncing, so we'd like to provide an explanation to help clear this up for users! Most of these questions have surrounded the impact of those changes on some users' activities with partner apps, especially Pact and Humana Vitality.
The biggest points of confusion seem to be regarding calorie change and distance change after an activity has synced to the server, and if there are some slight decreases which bring the totals below minimum thresholds, users have not been able to qualify for completion of an activity in Pact or Humana Vitality, among others.
In our Calorie Calculation article, we list some of the factors which contribute to calorie calculation, and add a note that this number will likely change after syncing. This change happens because when your activity is sent to our servers, more accurate GPS information about your trip can be accessed and thus we recalculate your trip to provide a more accurate overview.
However, this change doesn't apply to just calories. You should expect to see minor changes in distance and time as well, as the GPS points will be calculated more accurately than they were in real time. This will impact your overall trip data more often than not, but it's a good thing!
We recommend that if you are completing an activity in connection with a partner app which has certain requirements for the activity to "count," it is best to do more than the minimum threshold.
For example, if you were to set a Pact that you'll do 30 minutes of exercise every day with Runkeeper, it would be best to do 31 or 32 instead, just in case! Overestimating is the best way to provide a cushion which will account for these changes, and it'll also keep you healthier. :)