Having done thousands of runs and tested myself a good number of times, I feel that I have pretty accurate heart rate zones.  When doing easy paced runs, my heart rate is normally well within the Zone 1 or Zone 2 range.  On my easy paced run today, my heart rate got a little elevated.

On this run, my heart rate drifted into Zone 3 for almost 40% of my run time.  I didn’t feel like I was pushing the effort, so why was my heart rate a little elevated?   Is it something to worry about?

The simple answer is “no”; I should not be worried about it.  These kind of things happen sometimes.  I strongly suspect that my heart rate was a little high, because it was unusually hot and humid this evening.  I am pretty sure that my heart was working a little harder than normal, to try and keep my body cool.

The bottom line is that is is good to monitor heart rate while training, but equally, don’t get too hung up on one or two data points.   There is always variation and sometimes the data is a little high and sometimes it is a little low.

I will keep an eye on my heart rate during other runs this week, but won’t necessarily react to it during a workout.  My guess is that it will behave normally for the rest of the week.