Red (clearly elevated HR)
→ reduce difficulty more significantly (PL -1.0)
→ or, in more extreme cases,
→ automatically switch from Hard Intervals → Endurance
Why this makes sense
This would allow:
reacting before the main intervals start
reducing risk of failed workouts
improving long-term consistency
keeping the athlete in the “productive” zone instead of forcing sessions on bad days
Why it could work well in TrainerRoad
Since most TR workouts are done indoors:
conditions are relatively stable
repeatability is high
This creates a good environment for:
establishing a personal HR baseline
detecting deviations reliably
Important note
This is not about fixed numbers.
Everyone would have:
their own reference power
their own HR baseline
The value comes from consistency over time, not absolute values.
Question to the community
Do you observe something similar during warm-up?
Do you use HR in the first minutes as a readiness check?
Would you trust TrainerRoad to adjust workouts based on this kind of signal?
I’m curious if this is just a personal pattern or something more universal.
Short answer: This is a personal pattern. Frequently when I’m feeling great and getting ready to hammer, my heart rate will be running elevated from base. It’s not always a sign that things are bad, it can be good.
Conversely, fatigue can show as a depressed Heart Rate or an inability to get HR as high.
And, for some people HR isn’t as consistent.
So - I’d treat these as observational for you personally, but don’t think you can rely on them or use them consistently in the way you propose.
The general concept isn’t bad, but lots of bad assumptions in my opinion. An unresponsive (ie low) hr is often a sign of excess fatigue. And things like caffeine and temp can swing the rate significantly as well. Not that those things couldn’t be baked into a solution, just saying that looking at hr alone after a short spin is not broadly indicative of training readiness.
That’s fine, just calling it out. I’ve been in and out of Claude doing research all morning myself…
Regarding your proposal - I think it’s good to have a personal framework for these things and knowing how you personally react. Heart rate, RPE, HRV are all part of it for me. But, it’s contextual and you can’t say that an elevated heart rate is necessarily a bad thing, or low a good thing…
TR has said they’re capturing HR data and starting to incorporate it into their models, so pretty sure it’s a work in progress for them anyways.
TLDR For me: No, I wouldn’t trust this in isolation, because it goes both ways based on other factors.
That’s actually a really good point about not relying on a single signal in isolation.
It made me rethink the idea a bit - maybe full automation isn’t even the best direction here.
Instead, what could be really useful is giving the athlete more flexibility after the workout has already started.
For example, after the first few minutes of warm-up, based on HR, RPE, or just how you feel, you could choose:
-continue as planned
-reduce difficulty (e.g. lower PL version)
-switch to an easier alternate
-or even swap to Endurance
I know this is technically possible today by stopping the workout and picking another one, but it breaks the flow.
What I have in mind is more of a seamless adjustment within the same running workout, without interrupting it.
This way, everyone can use their own personal signals (HR, HRV, feel, etc.), without forcing a one-size-fits-all automatic system.
It would keep control in the athlete’s hands, but still make adjustments quick and seamless.
The easy way to do this is just reduce intensity using the existing in-app functionality, or just throw it in resistance mode and ride to RPE ignoring the workout.
I’ve been doing something similar for the past few months. I created two custom warm up workouts because (1) most TR warm ups are too short for me and the first work interval really really really sucks most times, and (2) I can tell how things are going to go based on my RPE and HR at the end of one of these warm ups. This is based on my experience only.
I agree trying to automate this would require more than just HR but the idea of warm up period performance being predictive of work out performance applies in my case.
That’s actually really interesting — I’ve been seeing something very similar. Mine is a bit simpler (just HR at a fixed power early in the warm-up), but same idea — you kind of already know how the workout will go. I like your idea of a longer / more structured warm-up, that probably makes it more reliable.
Do you actually change the workout based on that, or just use it as a check?
It depends on the workout. If it is something I think would put me on my limit on a good day then I drop the workout level a few notches. Otherwise, I stick with the planned workout and see how it goes.
In my experience, how you feel during/after a warmup can be misleading and I wouldn’t want to alter my plans based on that. I’ll always at least try the first interval and sometimes even a second (if they are short) before I pass judgement. Lousy legs during the warmup often open up once you push a bit. And not every interval session has to be done on perfect legs.
The idea
Proposed dynamic adaptation (TrainerRoad idea)
Green (HR within baseline)
Yellow (slightly elevated HR)
Red (clearly elevated HR)
but the idea is mine — just wanted to structure it clearly.