I have a garmin watch on me at all times which regularly records my heartrate. My resting heart rate is always recorded at 40-45. During my physical the doctor had me at 44. During my hard workouts my heart rate rarely goes over 175. I recently ran a PR 8k and my watch had me averaging 163 and a max HR of 179 during the race. I feel like my heart rate should have been higher considering how hard I pushed it. I am usually always pretty tired no matter how much I sleep. Does this mean anything about possibly being over trained? Any thoughts on this?