I'm still reading and learning. I've always wanted to ask this. Can you glean anything from the ramp rate of your HR during different types of intervals? Or the curve or linear ramp of HR back down as you rest after the work period.

Let's take a 3 minute interval. Your HR ramps up sharply and linearly for the first minute. Then there's this little slope as the ramp rate slows down. Then there's the new linear ramp going up and maybe leveling off.

What can you infer from the slopes of these curves (or inflection point), or if the curve almost levels completely during the effort?

Example:
For the 3 minute efforts I notice it does as described, but around 30 seconds to go it levels off. Almost like it could go to 5 minutes if you had the gas.

Does that mean the heart/lungs have it for that effort right now, but the mitochondria and your lactic tolerance doesn't yet?

I'm willing to listen to stuff here. I find this interesting. Just wondering if it means the work is too hard or too easy, or if it means I'm fatigued or not.

Example workout:
https://www.strava.com/activities/1809955071/overview


To prove I searched, I found this: I tried to make sense of it but could not
https://pdfs.semanticscholar.org/7172/823bc5996ba15db0032050f565fd827f7519.pdf