If I do a Crossfit style karate workout (push ups, moving around, etc), I am out of breath with a heart rate as low as 110. At 150, my technique breaks down no matter how hard I concentrate. I've never been able to push myself hard enough to get 170, although I do take the watch off if I actually fight (heart rate is probably higher then).
Yet on my easy long runs, I average around 165 and max at 177, and this is really easy. I could probably carry on a cell phone conversation, play a trumpet or read a book if I wanted to. Above 180 for any time, I struggle, and max around 200 going up a long, steep hill as fast as I can.
Is this a measurement issue? Is the 645M, as a running watch, better able to measure a sustained heart rate with cadence and GPS distance and speed vs a quick rise and fall from movement in different directions? Or is my heart rate really that low at karate, and I am just not as aware of it on my runs?
