Fair enough, 2+2=4 and 8/2=4, so there is more than one way to calculate to get to the same answer.
Somebody has to start naming it correctly, hopefully the others will follow 
. Something like average training stress would me much better.
I think people are more confused by the fact that the line does not represent their fitness, but average load. How often i reed “why is my fitness not going up” etc.
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eFTP is basically an indicator of fitness, or performance on the day. There are so many factors that influence ‘fitness’, it is an abstract term and cannot (and should not) be turned in to a number. Heartrate should never be used as an indicator of, well, anything really, as it is a response and again subject to many variables.
I would call it something like ‘Total Load’ or ‘Combined Load’
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Looking at (e)FTP only makes sense for all-out workouts, imho.
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I would say for a time crunched person with 100% Job, Family and some other hobby, anything above 80 Fitness is quite high. To reach 80 TSS daily you would need to ride 90min each day at a good pace. If you have two days off (one for recovery, one for family) you would have to to do around 120min at a good pace.
Commuting August 2nd to 6th
5 days
514 TSS
7,5h
172km
Not too hard 
Le_wou’s data: 514 TSS in 7.5 h implies 68.5 TSS/h which implies IF = 0.828. Ie you were riding with your normalised power equivalent to nearly 83 per cent of your FTP, which is mid tempo by intervals.icu classification. Brisk but not hard, so long as there are not too making coasting events for downhill or stop lights.
@Urs_Leuthold: an average of 80 TSS/day = 760 / week = 152 every 5 days. Assuming 90 minutes per day, this implies 100 TSS / hour, which is riding at FTP all workout, everyday.
Assuming 2 hour workouts implies 76 TSS / hour which implies IF ~ 0.87, or high tempo.
But all that assumes constant power riding. If you do some VO2 max work and some threshold work, then the sums might look like this:
0.5 h at 120% of FTP, split into intervals, implies 72 TSS.
2 sets of 1 h at threshold perhaps split into intervals implies 200 TSS.
1.5 h at 70% as recovery for the VO2max work implies 73 TSS
2.0 h at 70% as recovery for the two threshold workouts implies 98 TSS.
That adds up to ~ 445 TSS, leaving 315 TSS for the other two days. With two 2-hour workouts, that’s ~ 79 TSS / h, or IF ~ 0.89, top of tempo range.
You’re right, Urs, that’s brisk. You really need one 4 h ride / week at endurance / low tempo pace to get the TSS you’re thinking about. And that implies weekly hours of 12 at least.
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Where there is a will there always is a way. And where there is no license there is a must 
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I agree that renaming the “Fitness” graph to something that more accurately describes what it shows ( CTL or “average stress balance”) would be helpful for folks who are leaning to self-coach.
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This one is realy, really excellent. Especially the last part, where it’s about “the ugly” (61:00…)
Strongly recommendable for TSS/CTL hunters (like me 
)
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Hey there,
hijacking this thread for a question:
I think I have understood the math behind Fitness, Fatigue and Form.
So just checking: in the recent weeks I have done a few workouts that really stand out w.r.t. traiing load. Even though they are dating back ~one month I think they still have their influence on todays calculated Fitness, Fatigue and Form. As a result according to the graph I am today in the “fresh zone”, which I would normally interprete as “there really hsn’t been much training load recently”. However, I have done quite some intense workouts recently, only these don’t compare o the three big ones mentioned above.
My question realls is: in how far do such “extreme” workouts distort the interpretation of the graph?
Cheers
Well they might put you into the red zone which probably isn’t right for just one workout. You can see the influence in the bump on the fitness line. If you pick a date some way into the future and do not have any planned workouts you can see how the curve drops off.
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It’s a great shout.
Don’t think of it as metabolic fitness in the same way as VO2max helps stratify our individual physiological (age related) fitness, that we could compare one person to another.
It’s a great marker by which to track progress and point in time readiness for whatever goal is set. It’s more a fitness/readiness for purpose/goal than that metabolic fitness thing.
Last year, my goal was Lands End to John O’Groats. I needed my ‘fitness’ marker to reflect moment in time and progress, based significantly on saddle time including back to back long rides. I could easily have smashed the ‘fitness’ numbers with shorter tempo rides or even LTintervals. I’d have had a great type of fitness. Just not the sort rrequired.
Sadly, this year, I’m signed up for some time trialling. I excel at being rubbish at them. My fitness marker has to reflect a different blend of sessions from last year.
That’s how I read it, anyway.
Fitness for purpose.
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I will compare to weightlifting…just easier to understand fitness concept i think. You start lifting with 10kg, and you could lift 10kg for your whole life but instead you decided to add every day some kgs.
After couple of months you lift 100kg every day! Wow! (thats your 100 TSS, 1kg is not 1TT but assume it is for this example to work), three hard workouts on your graph represent days when you lifted 120kg or even 140kg on the second hard day. It was hard but you were prepared, it’s not that far from your everyday 100kg standard and you had a great day, happens 
Every extra weight put some strain on your body, so the body needs to adapt to new weights. It was used to lift 100kg, felt good with it, now it’s something new so body decides to improve muscles a little and needs some rest and good meal to do it properly. After couple of days you are in a fresh zone well rested but you must remember that your body learned how to lift 120kg, and more importantly prepared for next 120kg which will come. So every next 100kg day is easier for your body and the muscles can only be disappointed, after some days muscles are getting bored and are slowly rebuilding the fibers again for lower weights. So the proper training is managing between resting your body and pushing to higher and higher weights without risking overloading and injury. And that graph helps visualise when to push and rest, ofc it’s only a graph so watching your body is most crucial.
It would be wise to progress slowly but still to progres. You decided to go faster and you did succeed with a small risk of injury or falling down under the weight. The real question is why you consider your gain as a distortion? And why you didn’t accept that you can lift 120kg now and are not slowly preparing for 150kg or resting some more and starting in a lifting cup? I know it’s hard to imagine but the three hard workouts you did are kind of your new standard. And you can’t say you are a 100kg guy who accidentaly lifted 120 kg three times, in worse scenerio you are a 120kg guy who is resting after a hard season and hopefully will beat this record next year only gripe being, next year you will start maybe not from 10kg but not from 120kg for sure, maybe from 40-50 if you do some other stuff during the winter:)
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Hi there, can someone give me some inquiry on my fitness score if i inserted by mistake some bad values or if the fitness calculations are correct from my profile?!
I did a 20min ftp test 28.02.2022 (28 February) but my aerobic capacity and heart stopped me from pushing harder, my legs were pretty fresh.Heart rate,power values,weight are all spot on.
Rides are done on a tax trainer with favero assiomas pedals(dual)
As you see i currently do not workout every day and i have plenty rest days i always feel fresh, some times i just do some simple exercises with body weight if don't have time and estimate my training load but it doesn't add up for the current week.
What changes i need to make in my settings?
Why my estimated ftp overrides my tested ftp?
p.s. My profile Intervals.icu
More or less at the bottom of the settings page there is a table that defines how much different kinds of activity contribute to Finiteness and Fatigue. might have to add “workout” or similar.
thanks, i have planned the weight training but forgot to check the box for done workout, that issue is resolved it will add up, the rest of fitness fatigue and and overriding my ftp remains, maybe someone that knows the calculations of the application.
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