i have searched the forums and never found the answer, so i finally decided after witnessing this problem again and again, i'd post here:
in short, in both iOS9 and iOS10, the Garmin Connect App in iOS drains my iPhone's battery even if background refresh is turned off. the only way i can stop the draining is to remember to force quit (using the task manager) the app after using it to sync activities/etc. with my watch.
is there any setting/fix for this problem? if i look in the Battery Setting on my phone, i can see hours of background usage by the Connect App.
thanks for any thoughts/suggestions.