Originally Posted by merlinextraligh

Which is not much more than random luck. For any given individual, that chart can be off wildly. For me, my LTHR is right at 100% on the chart, my max is 25 beats above the chart, and I've done 40k TT's at 8 beats above what the chart says is my maximum.

And actually, it's low for you as well. That 142bpm puts you in V02 max zone. You can't clim 40 flights of stairs and be in that zone the entire time. The chart predicts that your HR for that effort should have been closer to 125