Formula for "value" of a workout?

Hello folks,

To be more specific, is there a formula for the “value” of a workout that was immediately preceded by another workout?

Yesterday due to raised humidity I decided to swap out my scheduled Tallac +3 with its 5 x 15 SS intervals spanning 120 minutes, instead opting for Avalanche Spire -1 with its shorter intervals but higher intensity of 5 x 6 minute O/U spanning 60 minutes and then immediately followed by 90 minutes of Brasstown Zone 2.

The 90 minute Zone 2 felt more difficult than if I had foregone the O/U workout and stuck to only the Zone 2 for the day - no surprises here. And yet the calculated TSS is the same for the Zone 2 workout in either scenario, even though the TSS feels more TSS’y (haha) having done the preceding workout.

I think that summing the TSS of both workouts isn’t quite the right solution, as I could have instead started with a 30 minute sprint/VO2max workout with less TSS but causing a similar muscular fatigue effect going into the Zone 2 workout.

Of course this question extends into a scenario where I could have made it one single workout of 150 minutes, perhaps manually padding the O/U workout with an extra 90 minutes of Zone 2. I just feel that that second portion on its own should have more value than if I had only done the Zone 2 for the day. I think it does have more value, but there’s no calculation/formula for it?

Any thoughts?


WKO5 gives a Training Impact Score, that will e you a pretty good idea of the anaerobic and aerobic impact of any session. This will probably be what you need.

TSS calculation doesn’t take into account what you’ve done earlier in the day/week/etc. It’s up to you and your goals to decide whether doing a workout when you’re already tired is of greater or lesser value. If adding the Z2 work after the over-unders puts your daily TSS way over what your plan called for that day it would likely be less beneficial than not doing it at all.

Edit to note: had you made it into one 150min workout the TSS calculation would still have been the same. I can’t tell if that was clear to you or not.