From my knowledge as a fitness instructor, when people push their exercise beyond there fitness level, then their heart rate stays high for a prolonged time after exercise. So, the next time you exercise try to decrease the intensity of the exercise and keep your heart no higher than 150bpm.
When raising your heart rate to 170 that is only for trained athletes who want to increase their cardiovascular level. To stay healthy and stay in the fat burning zone, 170 is much to high.
Thank you, my concern is that on that specific day all I had done was go for a 2.2 mile run. I did not push myself or nor did I feel pushed it's just that I feel like my body is still working after a run or sometimes without any exercise. Also anything that I may exert energy doing, I can feel my heart racing sometimes for up to a few hours.