TSS fudge factor when using machines

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  • #65595

    Hi coaches – used to adding fudge factor for TSS when carrying 20% BW pack when doing hilly hikes based on hight gain.

    What is your recommendation for a TSS fudge factor when using same weight but on incline trainer or stairmaster?

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    MarkPostle on #65603

    Matt, When using fudge factors for folks that are combining indoors and outdoor training I feel like the machines justify some fudging but not as much as outdoors. Outdoors always seems harder and I think provides a little more training stress for the given vertical but also the eccentric loading of the down doesn’t exist on the machines. Thinking about it in those terms I give machine vertical gain half the fudge that I do for the equivalent vertical gain and loss outdoors. That is to say for every 1000′ of up I add 5 TSS points.

    keith brown on #65859

    This might be referenced somewhere else, but what is a fudge factor and how is it used?

    mattmay3s on #65861

    Hey Keith if you put ‘fudge’ in the search bar on the website you can see the whole article but here is the fudge bit:

    hrTSS “Fudge Factors”
    So what is an uphill athlete to do? It’s not a perfect solution, but I and the other coaches at Uphill Athlete introduce specific fudge factors into the hrTSS scores for daily workouts. Note: For the sake of comparing your workouts, it is important to remain consistent in how you apply these fudge factors. That way you will always be comparing apples to apples.

    Here is the system we have developed, broken down by workout type:

    A purely aerobic run/hike/ski while carrying no to minimal weight:
    Calculate the TrainingPeaks hrTSS and add 10 TSS for each 1,000 vertical feet of gain.

    A purely aerobic run/hike/ski while carrying more than 10 percent of body weight:
    Add 20 TSS/1,000 feet.

    keith brown on #65863

    Excellent – Thanks!

    Nate Emerson on #66115

    Clarification on the fudge factors:
    1) Elevation gain & loss:
    With outdoor training as the default setting, it’s been implied that the athlete is also descending. So adding 10TSS assumes 1000ft of elevation gain AND 1000ft of elevation loss.
    For program composition, you could assume slightly more metabolic training stress comes from the ascent (assuming walking/hiking for both ascent and descent), and slightly more muscular stress comes from the higher eccentric loading on the descent.
    2) For weighted carries:
    Add 10TSS for every 10%BW increment for 1000ft gain & loss, or 5TSS for for every 10%BW increment for 1000ft gain in isolation (i.e. indoor workout with no descent)
    3) Muscular Endurance TSS (which can apply differently indoors and outdoors):
    For hard ME workouts, additional TSS can be added if the workout leaves you extra sore for more than a day. This is very subjective, but over time you may recognize the impact of these workouts and what your personal TSS fudge factor might be. As coaches, when we recognize that an athlete is quite sore well after one of these workouts (e.g. 36hrs, 48hrs, or even later), we’ll often add more TSS to these workouts retroactively.
    4) Different athletes respond quite differently to these stresses (e.g. some athletes easily tolerate descending with weight, while others can be sore for days). It’s most important to use TSS modifications consistently for yourself, and recognize when (or if) you need to modify your personal TSS fudge factors. For example, I’ve always done a majority of my training outdoors, and find that my indoor/outdoor performance is very similar at many HR intensities (often this is grade dependent), so I only have a few select TSS mods between indoors/outdoors. It’s important to recognize your movement economy and efficiency to understand whether you need to scale TSS fudge factors.

    For more discussion on all of these bullets, see this thread in the general forum:

    TSS "Fudge Factor" question

    keith brown on #66123

    Thanks Nate!!

    bill on #66134

    I am curious (and a little skeptical) about adjustments like this… my biggest question is what’s the goal? More accurate CTL? Something else? More importantly, does using them improve outcomes? For example, does it lower the probability of over-training?


    krish on #66395

    Just to clarify, if I do a hike with 1600ft elevation gain and also 1600ft elevation loss at 20%BW, is the fudge factor 30?

    That is, is it 10TSS for the elevation gain+loss plus 2x 10TSS for the (10+10)%BW?

    10TSS for elevation gain+loss
    10TSS for first 10%BW
    10TSS for second 10%BW


    Nate Emerson on #66407

    Krish, that’s correct. Good example for mountaineers.

    krish on #66408

    Thanks, that’s super helpful.

    Final ques/statement….this ends up making the Planned TSS much smaller (at times) than the Completed TSS. Is that expected given that TP doesn’t account for elevation and BW? How should we generally view the Planned TSS values? (I assume they’re heavily reliant on the AnT value.) Thanks again!

    Nate Emerson on #66410

    Another great question.

    Planned TSS is helpful for building out your schedule and forecasting training loads and recovery.
    What you are seeing with the difference between planned and completed is expected.
    If you want to make this cleaner in your planning, I suggest modifying your planned TSS if you think that you’ll be having major elevation change and weighted carries.
    If a workout’s planned TSS is based off workout builder or other metrics (yes- AnT and IF), it won’t take into account major elevation gain/loss and especially weighted carries. I find that IF is more relevant for running and cycling workouts – there is more change to TSS from external factors with mountaineering training, so modifying TSS makes more sense than modifying IF. And planned TSS doesn’t take into account delayed recovery. So in cases like a very difficult ME workout, I might estimate my planned TSS based off of previously hard efforts. This is trial and error and it helps to have a longer TrainingPeaks history if you are doing this.

    Hope that helps!

    krish on #66411

    Yes, extremely helpful. Thank you Nate! Sometimes these values add unnecessary mental stress, so it’s nice to know which ones to really care about and which to just view as guides. Have a great weekend!!

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