Understanding TR's intensity estimates for rides without power data

This is something I’ve seen discussed a little in the past but I feel I’m still not clear on. So let me try to explain my point of confusion…

Example 1. A 45 minute CX race that goes to plan, HR pegged the full duration, finish race exhausted.

Example 2. A 4 hour hilly gravel race that goes to plan, HR has big peaks/valleys, finish the race exhausted.

Now, for example 1, this seem like an easy pick of ‘all out’ or ‘race pace’ from the menu of choices because I was doing just that, going all out the whole time.

But for example 2, the race has very hard parts (climbs), easy parts (descents), general “recovery/getting back into the groove” moments, etc. The full race isn’t spent on the limit but everything was “left on the course”.

Now, would that make example 2 ‘all out’ or ‘race pace’ or more of an average of the intensities in the race making it something like ‘uncomfortable’ or ‘hard’? I wasn’t going an all out pace the whole duration like the cx race, but if I did I wouldn’t have been able to finish. But for a 4 hour effort it was all I had for 4 hours so does that make it ‘all out’?

Any input is appreciated!

The “race pace” selection way over estimates TSS for longer races. Eg 4-5 hrs plus.

I would have thought TR would have factored this into their calculations but apparently not - or at least not sufficiently.

For example, if I select race pace for Leadville, I get 621 TSS. This would correspond to 0.79 IF for about 10 hours. TSS for others with power meters I have seen in the 400s.

I suspect they really have the intensity correlated more to power in relation to FTP. I use it with the idea the the easiest correlates to Recovery level efforts, and the hardest is significant time in Anaerobic zones.

Not sure that’s right, but it seems closer to my powered rides when I look at it like that.

I agree, that the current terms are ambiguous and likely problematic. Something should change there to make the current setup more clear. Or a change to something more realistic like Dave expected should be applied (factoring time more intelligently than what appears to be a simple Duration times Effort calc).

The “race pace” selection way over estimates TSS for longer races. Eg 4-5 hrs plus.

Pretty much what I was getting at I guess. If that is the case, I wonder what would be the correct way to estimate on longer rides and races?

I put in “uncomfortable” for Leadville and it gave me 441 TSS. Still maybe a little high.

I think the best way is to rate outside rides based on the average RPE for one hour of that ride.

On average, I was riding at an “uncomfortable” RPE for each hour of Leadville.

But a better solution would be for TR to improve (or at least clarify) the algorithm they use.