Hi, I've been running for about a year or two now. A comfortable pace for me is around 8:30 /mi however when I look at my heart rate zone I'm typically in zone 4 even though it doesn't feel that difficult. My garmin suggested pace for a base run is around 10 / mi which feels much too slow for me. Any recommendations as to what I should follow? Keep going with what is comfortable pace or try reducing effort based upon hr? Thanks!