Hey kocanez. I’m not an expert, I can’t give you a lot of advice. I just have general remark. It seems you tracked your heart rate with the Vivosmart 4 (wrist-based heart rate monitor)? Or did you wear an external chest strap? Because the heart rate measurements on the wrist are kind of unprecise. I mean for a constant activity (where your heartrate is constantly elevated) such as running they are usually “fine”, and I don’t think it is heavily off, but if you do interval training or exercises that only elevate your heartrate for a few seconds, then the wrist heartrate monitor is completely useless, because it’s too slow to catch up. I have observed this already quiet often with my Fenix 5. My advise would be to repeat your run with the chest-based heart rate monitor and compare the results.
Apart from that your heart rate of course heavily depends on your age. But it seems like you are also suffering from ADS, like me 😉