Heartrate lag, any use?

Training
1

i asked this on fasttalk, but got tumbleweed.

can we tell anything from heart rate lag - the delay between power peaks and heart rate peaks in cycling.

maybe is can be used as an indicator of fatigue, of fitness, maybe it is just noise,
or perhaps no-one has ever looked into it.

-Steve

2

I don’t have anything solid for you, and there are very knowledgeable users here on the forum who might have better insights. But yes, from experience, I know that an athlete under a higher accumulated training load will tend to have a more “sluggish,” “delayed,” or “laggy” heart rate response.
In fact, the most noticeable aspect isn’t the delay in heart rate increase relative to effort, but rather the amplitude of that increase. I’m not aware of any systematic approach or quantification of this response, though. It’s highly individual—extremely so—and can even vary within the same training session.
Possibly, the answer to this lies indirectly in HRV—Heart Rate Variability.

1 Like
3

It’s physiology. There is always a bit of lag between exertion and your cardio-vascular system response to it. There are papers in the physiology literature on heart rate dynamics and fitness. The heart rate recovery (i.e. the amount HR declines in the first minute or so after suddenly stopping exertion) is loosely related to fitness. This means the onset of the heart rate response to increased exertion likely is as well, but I do not know if it has been studied in detail.
My algorithm addresses this to a certain extent. I now have a ‘Demo’ set of data you can bring up to review. In each of these you will see the HR lag behind wattage, though you have to expand the scales a bit to see this in detail, and it is easioer to see with sharp ‘spikes’ in wattage. Drag with the mouse around 50 min (lower graph x-axis) on 16Oct24_NFP. Click the ‘Run Model’ button below the graph to see how the model also shows the delay.
here is the link (https://cyclewatts.pythonanywhere.com/), there is explanation of how to access the demos in Overview/Help link on the left side.

4

thanks to all.
interesting stuff.