How is the category difficulty calculated?

Sorry if this was already discussed / answered…

Can someone explain why Bashful -1 (73 TSS, 0.86 IF) is rated as VO2 Max 3.7 and Givens -3 (72 TSS, 0.85 IF) us rated as VO2 Max 5.5?

So does this mean Givens -3 has a higher intensity than Bashful -1 though TSS & IF are both a tiny bit lower?

So in the future when I look for a VO2 workout, I should look at that VO2 rating number and not the IF & TSS?


Here’s a blog post they did that will explain a lot… Introducing Workout Levels: A New Way to Understand A Workout's Difficulty - TrainerRoad Blog

Based on those intervals you used as an example;
2 1/2 minutes at 118% for me is a lot harder than 120% for 1 minute.
Someone on this forum who understands more about Vo2max workouts could probably explain more thoroughly.


thanks for the link. What you say is true but then the recovery in between is also longer. I get all messed up with these numbers… I thought I had it figured out but guess not. The worst is when I think a 0.86 for a 2 hour session is no big deal. I wonder if there is like a comparison chart or something that shows how a 2 hr 0.86 compares to a 1 hr session…

1 Like

Nate said on the podcast to ignore IF and TSS and just look at the level of the workout to get an understanding of how hard something is.


Got it, will give it a go.

For one minute you work more anaerobically than aerobicaly that is why. 1 min max effort is roughly 50%-50% contribution of those two systems. With 2,5 minutes you have burned a lot of anaerobic contribution and this is mainly aerobic effort (with smaller anaerobic contribution like almost always). Not to mention that lactate byproducts etc cannot build up so much with 1 min effort that is pretty low percentage of your max 1 min effort. 1 min “vo2 max” is not even vo2 max workout as your metabolism does not have any chance to catch up. So from the vo2 max training this a little bit useless workout, but more of a leg primer to accustom user with the higher intensities.


I think you’ve gotten good answers above, but just to weigh in - the example you’ve provided is a great example of why IF isn’t always the best measure

Doing 15 60 second intervals at 120% in an hour is going to be easier for most riders than 6 150 second intervals at 118%, and frankly it wouldn’t even be too close for most people


I find that IF can be deceiving because it can get diluted by the rest intervals and cooldowns, etc. as mentioned above the levels and difficulty score are a better way to gauge the “work” portion of the workout, Givens has more breaks which brings down the IF, but the work intervals are considerably harder than Bashful

1 Like

I’ve been putting in some 5 & 8 min VO2 Max intervals but those are not only physical but very mentally taxing as well. Drooling, gaging, talking to myself and counting the seconds….


Sounds about right :slight_smile: