Sudden increase in max training heart rate

KAV wrote:

Stop right there.... check that the HR is not locking on the cadence you are running at. It happens over and over and over.... When people start seeing values at 170/180 that could be the watch has gone crazy. Why it happens i don't know but there are hundreds of threads out there reporting this. In order to be sure that is (or not) the case try to put move the watch a lot higher from your wrist (almost on your armpit) if you are using a watch with an optical HR. Or, even better, try to use a chest strap. If you were running indeed at those HR values running would feel very a lot more labored - it depends obviously how old are you - most likely you wouldn't be able to run a full 10k at those values especially if it is normally around 160.

Yes, watch HR monitors should be deactivated immediately after purchase. Only chest straps are accurate, or as alternative, manually measuring the pulse.

I've done 500+ runs with a chest strap and 500+ bike rides, and some with optical HR. The difference is quite significant. IF someone decides to use HR, it's only worth it with a chest strap.