Just glancing at Zwiftpower and I noticed what I think is a new column labelled Hrr/HReff. It seems that as the Hrr goes up, the HReff goes down. My first impression is that higher Hrr and lower HReff seem to be regarded as good things but I don’t understand how this is calculated or what it represents. My *higher* values seem to be associated with shorter, more intense events. My zwiftpower *best* of 1.67/45 corresponds with my highest average power in a 1 flat lap race. Anyone help me out here?

# Zwiftpower HR Data

Peter, I’ll look into it. Honestly, I don’t ever look at Zwiftpower, so I will have to look at what they are trying to get at with the data.

Apparently, the trick is to mouse-hover over the column description, which gives you the formula. (Ignore the fact that it’s not possible to do this on an iDevice, boo, hiss.)

Their definitions:

Hrr = HR ratio = avg power / avg heart rate

Hreff = HR efficiency = avg heart rate / avg w/kg

No idea whether these numbers are really meaningful.

Thanks @jlemon. That makes sense. With Average HR as the denominator for one number and the numerator for the other they would naturally move in opposite directions. My guess is that this is intended as a way to track aerobic fitness/efficiency over time - much like the MAF test we did at the beginning of this lab.Looking back at some numbers for the same courses over time I can see my numbers improving (Hrr going up, hreff going down)