Yes. The TSS and IF displayed are different for each user because they are calculated off your individual 4DP values.
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That depends on the type of workout.
In a workout at or below FTP, everyoneâs IF should be identical.
If a work out has significant NM, AC, or MAP efforts then they will vary greatly because those efforts will be above FTP in different ways for different individuals.
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Hmm. Never knew either of these. Seems like Iâm not alone in that, based on the number of times I see comments here that refer to âTHEâ TSS or IF scores in such a way that these are assumed to be the same for all.
Learned something new today!
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I probably should not have said identical, but around the same.
IF = NP/FTP
TSS = (NumberSeconds x NP x IF) / (FTP x 3600) x 100
NP (Normalized Power) = your weighted average power, so higher watts get rated more.
Here is the calculation from the Training Peaks website:
Step 1: Calculate the rolling average power with a window size of 30 seconds.
Start at 30s and calculate the average of the previous 30s and repeat
this for every second.
Step 2: Take each value from step one and take this value to the fourth power
(multiply this number by itself four times).
Step 3: Calculate the average of values from the previous step.
Step 4: Take the fourth root of the average from the previous step â this value
gives us the normalized power.
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Hmm
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Hereâs a little something about TSS and IF in a 4DP world from the before times.
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Thatâs a great read, Sir Glen! Thanks for sharing that.
Question: Are you implying with the âbefore timesâ that any of that article no longer applies?
Or are you simply referring to how the TSS and IF usage was (and IS) less useful in a 4DP world?
I noted that when I did the Bavaria: Burgburg workout 2 days ago, my ability to match the targets was definitely less successful than with most other workouts, though I did learn a little along the way and figure out how to hit them at least some of the time. And overall, I felt the workout didnât tax me as much as I expected it to.
My TSS was 11 points (about 20%) below the workout estimate, and my IF was .10 point (about 10%) below workout estimate, which I think is logical because I missed the target numbers often enough that the difference in total work output was significantly lower than it would have been had I met all the targets.
Whatâs counter-intuitive in that is that I was TRYING HARDER than usual to HIT the targets, but I wasnât getting out the power to reach the numbers.
This illustrates that how hard you FEEL like you are trying to achieve the workout demands isnât always very indicative of a TSS or IF score.
It may be on a given day that you just âdonât have it,â and your hard effort just wonât result in as much real work done, OR on another given day, when you may indeed âhave it,â you may NOT have sufficient knowledge and experience with your equipment AND with the best technique to PUT OUT WHAT YOU HAVE and the result will also not show as much real work done.
As I write that, it makes me think about the implications of specific workouts in a training plan, and how important the timing can be for which workouts you do on which days, i.e. getting the most benefit by being properly ready, rested, tested, taxed, or whatever scenario best applies to the demands of a particular workout on a particular day.
Iâve grown in my understanding of this over the years, and most of that growth has come through this forum and through SYSTM use. As Iâve stated many times, Iâm really not very geared in to âtrainingâ per se, and I break the rules of training logic VERY often to do an outdoor ride to just âgo wherever I want toâ that day.
But I do find that Iâm getting a little smarter and a little more willing to adjust my wishes in order to âbalance the budgetâ a little better! And it has usually paid off.
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Yeh that (and some might argue these concepts are not very useful anyway).
And, also, the âbefore timesâ was when Sir Neal and his team were still with The Company and involved very heavily. Iâm pretty sure theyâd review the data from completed vids and make adjustments based on their observations. Iâm not sure thatâs being done by anyone anymore, at least it doesnât seem that way.
Thereâs also a great little podcast, also from the before times on RPE that is worth a listen/read.
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Question: Are you implying with the âbefore timesâ that any of that article no longer applies?
I think they mean âbefore Wahooâ. This was written before the Sufferfest buyout I believe.
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I dunno about others, but generally, when I refer of the before times, Iâm not actually referring to before The Acquisition but specifically to before The Company started messing everything up. So if âIâ represent âtheyâ when you refer to âtheyâ then let me explainâŚ
The initial days of The Acquisition were heady and pretty exciting. While the old SUF app had some things that SYSTM still doesnât have (like being able to sort by date last ridden) the content had increased significantly. From all the On Location stuff, to the Pro Rides, to the whole A Week With series (which could really use a new addition 
) to the Inspiration channel to new SUF content.
For me, the before times was:
- before they fired the inimitable Sir Dylan and others who were at the heart of SUF
- before they abandoned their state of the art Sport Science centre not too long after opening it
- before they fired Sir Neal, Dr. Jinger and most, if not all of the coaches
- before Sir David left and, the final nailâŚ
- before Sir Francois left because the soul of The Sufferfest â which The Company, to this day seems to never have understood â had been gutted
The content coming from the Company now seems to lack the science it had before while using sciency language (perhaps even AI) to describe it.
You are 100% correct though, @donut_boy, the original version of that article was first posted on January 6, 2018 so even BEFORE, the before times, when they listed the author and the date it was written
4DP was introduced in 2017, well before The Acquisition.
Here is a link to some articles, some of which have been retained by our friends from the Wayback Machine:
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I think that even before they set up the Sports Science Division, Neal Henderson was helping them design workouts. In a podcast with the Escape Collective, Neal Henderson mentioned 4DP and Full Frontal as something he did with Sufferfest. Full Frontal and 4DP certainly existed before the Science Division was set up.
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Oh yeh, 100%. Sorta. Sir Neal was designing workouts for SUF since 2013 before the SUF Science Division was set up.
Sir âNeal first began using his evil genius in service of the Nation of Sufferlandria back in 2013 when he created the workout for the two-hour threshing machine we call Blender.â
What I was referring to earlier, was the state of the art Sport Science centre (not the SUF Sport Science division) The Company set up in Boulder, CO (and Simon from GCN visited) then shuttered it and fired the team.
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Yes. And itâs dynamicâif you change any of your numbers it will also change the order of the workouts if you âsort by TSSâ. Ran into that issue when I was trying to do all the Sufferfest workouts in Ascending TSS order.
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Relative to the dynamic nature of the scores, I wish that there was a record shown with the completed workouts that indicates what the TSS and IF scores WERE at the time I completed them. If Iâm seeing what I think I see, once that TSS and IF has been adjusted to your current performance data, you canât be sure what the EXPECTED score was when you did the workout; you only see what you DID and what the current rating is for the workout if you did it NOW.
It seems to me that a good understanding of how this works could be beneficial for assessing oneâs progress.
As it is, Iâm still a little uncertain how to interpret past performances on workouts relative to the current ratings.
And I also wonder about the more rare times that I see my TSS and IF score on a previously completed workout vary by a LARGER margin than the norm. For example, it seems I USUALLY am within a point of the targets on recent workouts, but on some, I was low by nearly 20% on TSS and nearly 10% on IF. (Bavaria: Burgburg is case in point.)
Does that simply mean I didnât put out enough Watts? (I was low on several interval targets in Burgburg.)
And is it true that if receive below target scores for TSS and IF, then the workout benefit was less than it should have been for me? And vice versa?
OR is it also possible that lower scores for TSS and IF on a workout could mean that my HR stayed lower than expected even if I DID hit the target power numbers, and maybe I wonât get the expected benefit from the workout because it wasnât taxing enough (though I think that could also mean Iâm overtraining and canât get HR up sufficiently)?
Iâm just mulling over how to interpret the differences from targets and actuals with these scores, and how to best learn from them.
I donât think HR affects IF or TSS.
If you click on view activity history you should get a list of the dates you rode the workout and some summary statistics like avg HR and power. If you click the ride entry on a particular date, you will see some stats like the 4dp numbers you were using, as well as the IF and TSS based on those numbers. At least those numbers were different on two ERG mode rides of The Best Way is Blended, the first one I checked. Now I feel obligated to ride it this afternoonâŚ
Yes, Iâve looked at the history, and I do see the TSS and IF based on what my 4DP was at the time, but what I wonder about is what were the targets for the TSS and IF at the time I completed the workout.
Those numbers are lost, as far as I can see, so I have no way of knowing if I actually met the TSS and IF that day or not. Thatâs what I wish was still visible.
I canât honestly say whether knowing this would be meaningful or useful. I just wonder about it, just as I like seeing what my 4DP was at a certain time in the past (which I can see.)
I suppose it just adds a bit more point of reference for that past data.