Pettit outside - double TSS?

So as it was a nice day this morning, and I wanted to work on body position, I did Pettit outside. Now if you do this workout outside, it becomes a 90 minute ride. I stuck in the suggested wattage window for almost the entire ride, a couple of brief accelerations from junctions aside, and one very short effort (less than 60s) up a sharp little rise. My average watts and weighted average were in range. Yet the TSS of the ride is almost double: any suggestions why?

Ignore TSS.

I think that’s a TR error maybe, not the calculation but the TSS estimate. The TSS on a 1.5 hour version of that ride should be 70 TSS.


File a ticket?

TR indoor/outdoor is a bit goofy. It might have to do with their old adage where TR stated indoor rides are ~50% harder than outdoor rides? I can’t say if that’s what they intended. I think there’s another thread going on about indoor/outdoor.

For all indoor/outdoor rides, it seems they just copy the TSS value but it seems, at least on some, that the duration is increased a lot with the same power target. So that means the TSS should increase accordingly, but it doesn’t.

Another possibility is that they mean total time, which is odd because I only go by ride time. So when a coach says ride for 3 hrs in Z2, he doesn’t mean to include the stoppages.

1 Like

I might file one, not because this workout bugs me that much, but because working from home means I will now have the chance to do c.50% of my workouts outdoors, weather permitting, and if the TSS on all of them is goofy, then that might be an issue.

I tried very hard on that ride to keep pressure on the pedals whenever possible, and picked a route with minimal turns and junctions (and hills) with that in mind:

Not perfect, but a good effort in real world on road conditions.

For sure, that looks great. Everything for me is a a climb or a descent, so I can only do something like this if I drive to a flat area…which defeats the purpose entirely. Maybe if I had pro watts…

Because TR needs to fix endurance outside rides?

Here is the outside prescription for Pettit:

Warm Up:

  • Ride for 5 minutes, gradually raising your power from 124 to 149.

Main Set:

  • 81 minutes in between 149-174 watts.


  • 4 minutes easy.

At low-end of ranges:

  • 5 minutes at 124W (50% FTP)
  • 81 minutes at 149W (60% FTP)
  • 4 minutes at 112W (45% FTP)
  • TSS = 52 (overall IF=0.59)

With main set at high-end of ranges, and warmup/cooldown at low-end:

  • 5 minutes at 124W (50% FTP)
  • 81 minutes at 174W (70% FTP)
  • 4 minutes at 112W (45% FTP)
  • TSS = 71 (overall IF=0.69)

The outside workout prescription for Pettit does not have a TSS of 39, it has a TSS ranging from roughly 52-71+. I’m really not sure what TR was thinking. Calling @IvyAudrain and I know you’ve discussed this in another thread, but IMHO this TSS discrepancy is really confusing.

That is one solution unless the additional time begins to impact future workouts.

If you pedal non-stop on aerobic endurance zone2 workouts, the other solution is to ignore the added time on outside workouts and just ride it for the inside workout duration (e.g. 60 minutes inside/outside for Pettit).


This is the direction I would go. You know what your area/routes are like. If you live in a area that is conducive to non-stop pedaling that just follow the indoor prescription. But if you live in an area that is more ride up/coast down the I would just adjust the time until you get the approximate TSS that you desire. But even in the hilliest areas, if it take 1.5 hours to get 1 hour of pedaling then you are probably doing something wrong or you are mountain biking.


Apologies for the delayed response, we’re looking into this and discussing in more detail as a team. I will for sure check in with more info as its available! Cheers.


Thanks Ivy!

1 Like

Another case:
Whorl, inside 50tss, outside 80tss… typo?

1 Like

Hey, all! UPDATE:

After connecting with the team and discussing outside v. inside workouts, we agree they should be updated to show a closer correlation in both duration and TSS.

We can see that feedback shows that athletes aren’t struggling with as many outdoor interruptions as we anticipated, therefore, it would be better to adjust those durations to align more closely with the indoor version. With some updates and releases rolling out shortly, we don’t know exactly when we’ll tackle these, but its now on the roadmap and we’ll certainly keep you all updated with new information.

Until then: feel free to continue to exercise some agency in shortening outside workouts how you see fit. As long as your intervals are completed there’s no need to tack on a bunch of extra TSS. Let me know if you have questions or need case-by-case help, of course.




Now I found the opposite: Laurentian indoors is 15min longer than the outside version. Seems that gives us time for a coffee-break on the trainer :wink:

1 Like

They are both 2 hours and 15 minutes.