I’ve just started the first week of Half Distance Triathlon Base Low Volume. For the bike portion the TSS is looking correct - I know TR has estimated TSS for the runs and nothing for the swim. Looking at the 3 runs I’ve completed this week with what Training Peaks has is vastly different. Example for a 35 min run at RPE 6 TR has it 29 TSS. For the same run in TP is has me at 57??? I realize TP uses rTSS and sTSS but is there a direct correlation? Also how accurate are these estimates?


Well TR is an RPE table based estimate; TP rTSS is pace based. If your threshold pace is accurate, rTSS is a better measure because it reflects what you actually did, not your perception of what you did extrapolated to a whole run.


TP uses your running pace zones that you have to calculate according to a 5K or 10K test to determine your Z4 Pace and your running LTHR and from there your running Zones, if you do not set those correctly values will be incorrect, it those are set correctly rTSS will be the correct TSS


Based on that should I be “slowing down” to keep in line with the TR plan? I guess I’m afraid of too much stress after just starting the plan which could adversely effect long term training goal.


Tough to say for sure, but you’re in a base period so a 35 minute run at 57 TSS correlates to an Intensity Factor close to 1. That means you’re running at functional threshold. Since you said you’re in your base phase, odds are one of two things is true: (1) you ran way too hard for the intent of the workout; or (2) your functional threshold is set too low in Training Peaks. I would bet the farm on #1, since that’s what most of us do. In the base phase of any long endurance event, you should be running much, much slower than you probably think. “Embarassingly slow” is a term I like to use.

For pacing information that could help you, check out Daniels Running Formula (book) or Greg MacMillan’s website with his pace calculator, which is also really good and generally aligns with Daniels.

To the calculator question, I don’t. I use either Training Peaks or, mostly now, Stryd’s RSS calculations for my stress values. Search running TSS estimations and a number of good calculators come up.


Thanks for the breakdown…interesting enough I have my THR at 170 within TP. That last run of 35 mins my HR average was 135 so you can see my confusion. I’ve been a big supporter if the “Run slow” model for 2 years now and it has reaped rewards.
I’ll keep digging on the TSS side of things! I have heard that eventually TR will be able to import run/swim activities directly into the calendar with TSS, time etc


rTSS in Training Peaks is calculated off of threshold pace rather than HR. If that is set too slow, that would also give you higher than realistic TSS. hrTSS is a separate calculation based off of threshold HR. And then TSS (for running) is calculated based off of running FTP if you have a Stryd or another power meter.

On TrainingPeaks, you can toggle between TSS calculations by going to the little drop down arrow next to the TSS box in the pop up window you get when you select the workout.