Towards the end of a 28 milerun I thought my HR readings were wrong. I had successfully kept readings to mid 130s or lower thanks to a walk/run approach. However, in the last few miles the readings went high & it took a good while to get them down.
Might this be due to a lack of food/carbs? I did take some food on board but maybe not enough soon enough.
So, does anyone know how I can tell if the readings are wrong?