Mismatched run load between pace, power & HR

Bug Reports
1

There is a mismatch in estimated load when building a run workout based on power, pace & HR metrics.

The following are the syntax for separate workouts and their estimated loads:

  • 1h 80% Pace
    (load=64)

  • 1h 80% power
    (load=64)

  • 1h 80% LTHR
    (load=45)

  • 1h 80% maxHR
    (load=64)

Given that the percentages for power and pace are based off the threshold value, I would have expected the LTHR workout to be roughly the same and for the MAXHR workout to be significantly higher but the MAXHR one is identical to the power and pace ones.

I understand that different algorithms may be being used for the different metrics but given the maxhr load is identical to the pace and power, this seems like a bug.

Thanks.

2

I experience a related issue where my planned workouts predict a training load that is lower (usually dramatically lower) than the actual load produced by completed the workout as prescribed. Since I use the form/fitness trend graphs regularly, I would appreciate if the planned load were more accurate for trying to keep myself in the green.

1 Like
3

And why do you think that 80% FTP is the same intensity as 80% LTHR?
80% FTP (Power) is well in the tempo zone
80% Threshold Pace is purely endurance
80% LTHR is low endurance, in many cases even recovery
So that clearly can’t produce the same load.
Just make sure to create your workouts with the same load metric as you perform your activity with. If you run by pace, create your workout with pace values, etc…

4

Did this today and am now getting the actual load matching planned load, thank you :slight_smile:

5

That’s a good point. However, It’s not so much that I would expect 80% FTP to have the same intensity as 80% LTHR. It’s that I would absolutely not expect 80% FTP to have the same intensity as 80% maxHR. Maybe I’m wrong here though.

As an aside, I would expect 100% FTP to be equivalent intensity to 100% LTHR and for these to diverge as intensity tends to 0.

6

80% HRmax will be somewhere in the tempo zone for most people. The fact that the above example turns out to be exactly that, is purely coincidental.

Theoretically yes, in practice not always. HR can be higher or lower then ‘normal’ or then the number that turned up during your last test depending on state of fatigue, temperature, hydration… Some days, 20m FTP feels much harder then other days and it can be reflected by a HR that is several beats off. And due to the lag of HR, load calculation is less precise.

Don’t forget that LTHR and FTP are spotchecks. They do vary day by day, not by a lot, but they do.

2 Likes