How does workout level relate to IF and TSS?

I noticed that workout levels dont correspond with IF and TSS. Compare these two:

Threshold 5.0
IF 0.91
TSS 124

Threshold 5.5
IF 0.85
TSS 109

You would think that Robion is the harder workout looking at IF. But it has the lower workout level. Am I missing something here?



Note that Hillaby has more “density” in the intervals with no gap between the first & second steps, where Robion does. Also note the much shorter recovery between intervals where 3.5 mins is harder compared to the longer 5 mins. That is all true, even though Robion has higher work percentage.

TR aims to make the Workout Level value look at and evaluate workouts based on the Work portion, but also the Recovery portion. Traditional measures like IF and TSS miss the recovery aspect since they don’t account for Work portions being combined, split, or spaced differently.

This is where the TR WL takes another step in helping identify the potential difficulty better than those older metrics.


Perfect explanation! Makes sense, thanks!

a simple way to look at it is, comparing two workouts. 1 workout has 4 10 minute threshold intervals with 5 minutes recovery between them. workout 2 has 1 40 minute threshold level with a 10 minute warm up and a 10 minute cooldown. They will have the same TSS and IF, but the 40 minute threshold workout will be a lot more challenging.