I see three load values on each activity from the different models - Power Load, Heart Rate Load, Pace Load. I’m using power load as default for Fitness plot (since Garmin power update arrived, HR before) but I’m also curious what patterns I should be able to detect by comparing the values across the activities - and/or whether I can use these to help calibrate the HR and power thresholds or zone settings.
I see a longer or harder run has all three loads higher than a short or easy run which is totally expected but the scaling is slightly non-linear due to the different criteria being measured and changing differently with effort intensity. Generally Power Load is higher than Pace Load is higher than HR Load across all activities (unless HR input data is obviously bogus). I’m not sure if that is just for me, or to be generally expected with run data coming from Garmin.
No particular question here. I’m just wondering if anyone else has thought about this.
The differences are mostly explained by technology.
About 4 decades ago, all we had was RPE and a stopwatch. We could only compare running/riding the same lap at a similar effort feel. Then came bike speed sensors allowing us to compare different sections of route at similar feel, under similar route and wind conditions. A bit later we had GPS allowing to do the same for running. Algorythms saw daylight to compare speed/pace under different route conditions taking elevation into acount. Now we have bike power, at this moment the best effort indicator because it is directly measured. Running power is still a calculation and not a direct measurement. Directly measured Power is the best indicator because it isn’t influenced by elevation, wind, surface conditions…
Pace/speed and GAP are becoming more and more reliable. HR is good for long steady state efforts but lacks for intervals because HR is always lagging.
For a steady effort on a flat road under similar conditions, Power, Pace and HR load should be very similar if your thresholds and zones are correctly set. If everything is setup correctly, Power and Pace for running should match pretty well. For cycling, wind has too much influence. Anything with hard efforts will have a HR load that is more off.
If you have devices measuring all three, prioritise Power over Pace over HR for load calculation to get the most consistent results.
This doesn’t mean that HR is a bad parameter, it can give you extra information on what is going on. Just learn to pay attention to the correct metric for the specific condition. Power can be seen as a measurement of external load, while HR shows internal load.
Thanks. I’ve been thinking like you suggest, that Power Load is what I manage to achieve and that HR load is the effort I had to put in to get there - and further that dividing one by the other might give an efficiency metric worth examining. The comparison would be most relevant when the route and pace are similar (say for Easy or steady pace Tempo and less so for Intervals where the HR and Power are less coupled). I might see an improvement as less HR load for the same Power Load at the end v the start of a training cycle.
But so far I don’t have a lot of data points for myself and any plots are quite noisy. I’ll definitely be looking for such patterns again when I have more data.
I ran a 8km race at pretty much ideal performance/result and got a suggestion to increase the FTP setting by 30W. I accepted the new setting and find I’m now getting power load figures for that race and later runs that are more in line with the HR based load (where for some time I’ve had the max HR set to the highest believable max HR I’ve seen in the last year or so).
I’m now less worried about a single load graph showing HR based load from before and power load from now. Absolute value doesn’t mean much but I’d like consistently scaled values to keep the Fitness/Fatigue plot continuous over time. With FTP set lower I was obviously getting higher power for the effort I put in resulting in slightly increased reported power load (v HR). I hadn’t wanted to guess the FTP figure that would balance these better so I appreciate the smarts in the processing that has helped. I think both are reasonably well calibrated for now.
There is also the thing with heart rate creep: for this reason, HR is not good for intervals. The last interval will have a higher HR than the first one, even if executed at same pace.
Then obviously pace is not reliable if you have lots of inclines, and also not if you’re running on a treadmill (Garmin tries to figure out tour corresponding pace based on your hand motions and heart rate).
The idea of comparing these metrics, particularly when route and pace are consistent, seems like a valuable approach to understanding your training progress.