HR TSS Estimate

Has anybody else noticed you can enable a TSS estimate from HR data? I know it’s been asked for a lot but haven’t seen an announcement or thread about it.

On the webpage, go to your account and then TSS estimation. Enter your max cycling HR, birthday and then select if you want this estimate for all rides, future rides or you decide per ride.

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I cannot find this setting on my account.

Shouldn’t this be calculated from LTHR instead of max?

Yes, I use this all the time for commutes on my single speed, it’s okish.

I think it’s part of the AT beta. I had a popup about it following an outdoor ride on my MTB which doesn’t have a power meter.

That raised a bug (for non-USA users) in that my date of birth was in dd/mm/yyyy format and it crashed the code. So if you don’t use the US mm/dd/yyyy format then that’s something to be aware of - just put 01/01/yyyy since being a few months out isn’t going to make any difference to the usual HR algorithms.

The maxHR value was also odd, 202, I think it picked up an erroneous spike in the HR data rather than a value that existed for a few seconds. I’ve had Garmins give weird readings when near railway overhead cables for example. 202bpm would have me heading to the nearest cardiac unit!

I have been using it, it seems reasonably OK for normal rides but for recovery rides/very easy rides the numbers seem to be quite high.

I also have connected and they explain how the HR TSS calculation works there - they build a regression model using your rides with HR and power to estimate TSS for rides without power.

I did a hard ride Saturday and Intervals and TR were within 1 TSS of each other (329 vs 330), but last night I did 1h45 easy and got 47 from Intervals and 90 from TR, which is a big discrepancy. Based on RPE, average HR, time in HR zones etc etc. I am much more comfortable with the 47. 90 seems a drastic overestimate. Strava relative effort was only 31 for the ride too, usually when I have power the HR based relative effort and TSS are rather closer together.

Fortunately, you can still set the TSS the old fashioned way so it’s no big deal really.


I’ve only been in the Beta since yesterday but have checked a few outdoor rides utilising the new HR TSS estimate and have also found it to be high.

I sent a little explanation to TR Support today:

…you appear to have an HR based TSS estimation for outside rides now. I have been using the Strava/Stravastix/Elevate TSS estimation for all of my outdoor rides. However, I have just checked a few using the TR HR estimation and there seems to be a considerable discrepancy.

For example. This mornings outside ride got 38 in Strava, but 62 in TR. And a previous one got 39 on Strava, but 64 in TR. Comparing this to my indoor trainer rides, this doesnt add up. For an hours VO2max workout I am getting approx 60-70 TSS and for an hours endurance, around 35-45. Based on HR, and endurance ride is about Average 130 HR whereas a VO is average 155 with a peak of 175 ish. Therefore for an hour outside, where I am averaging 130 and a peak of 155, you would expect it to come in around 40 TSS, not 62?

Bit rambly but you might get the idea :blush:

To be fair, one of the known AT issues is that the HR TSS isn’t working correctly, so could be related to that…

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Ah, I missed that on the AT page previously, thanks.

I recently got into AT too and must have missed the TSS announcement.

From the comments above, it seems to have the typical TSS from HR issues meaning it’s a ballpark estimate but not perfect. Hopefully over time AT will learn and improve the calculation.

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It’s far from fully baked.
Today’s 2hr gravel ride with a 69% average HR is estimated at higher than 0.9 - race pace - WTF?


That does sound high for a 2hr ride. i assume you have done, but have you checked what TR thinks your max HR is?

FWIW, for me, I find the TR number to be close to the one suggested by now, and Intervals helpfully shows you the number it would have used for HR based estimate even when you’ve used power, so you can get a bit of a sense check. Here’s my ride yesterday:

Both Intervals and TR have a lot of data from me with HR and power, and HR alone, so I find the Intervals estimate is usually quite good unless there’s something else going on (it is very hot, I am very tired, I have a hangover etc etc…) which throws my HR off.

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Anyone else think that the automated TSS estimation is significantly overestimating outdoor rides without PM but with HR?
I find that my rides are given a much higher TSS on TR versus

@adrian_r I moved your post under an existing topic with comments to review.

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I’ve been using HR TSS on TrainingPeaks for 5 or 6 years. TR’s estimates are often similar to TrainingPeaks, however I do see some TR estimates that are too low. Reported that to TR Support and they said it was a known issue, and workaround was to use RPE.

Maybe it’s worth noting that my rides have been trail riding. so a good portion would be descending.
Anyhow, it just seemed to be very high versus, and if using the manual option of choosing “intensity”. I would have to choose “race pace” to get equivalent TSS, on a ride where >80% was zone 2 or below

mine were road cycling, from 2016, at race pace with TR estimates being too low. But I haven’t paid much attention as since October 2016 about 99% of my indoor and outdoor rides have the same power meter.

Do you use How do the numbers compare?

I have an account, and look at it maybe once a month. Never bothered to look at HR TSS in as nearly 100% of my rides since October 2016 have been with power.

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The nice thing about is they give an estimated HrTSS for all rides to compare with the calculated load from power which is why I was asking. I don’t have an active TP so can’t compare to it. I have a few power meters so its nice to be able to do a quick check with HrTSS to make sure they are in line with each other if the TSS seems off