Originally Posted by
BlazingPedals
How are you determining your MHR? Formulas often give you inaccurate numbers.
I'm using the 220-age. That puts me right at 165. Z4 is about 132-149. The 220-age formula has always been close for me, but I know it's not right for everyone. My maximum riding effort so far has been about 163, so I figured 165 was about right.