Calculate Needed Training Load?

Jason: The green zone means that your 7-day average TSS is 10-30 more than your 42-day average [if you use absolute values. If you use percentages, then it’s 10-30%]. You know your 42-day average [“Fitness”], so adding 10-30 [or 10-30%] to that gives you the target you are looking for. There may be a bit of variation in this if your 42-day average has fluctuated a lot in the past, but this calculation will produce the number you want, over time.

But – this is a very steep increase in training load. I’d be very wary of such a rapid rise in training load.

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What phase are you currently in?

  • Early base
  • Late base
  • Early build
  • Other

sorry i dont know what that means

Rapid rise in training load? Isn’t staying in the green optimal zone the point?

So this morning I did a bike trainer with training load of 48 and a treadmill session with training load of 28 and my fatigue is 71 for the day - fitness is 57 = -14 form

I’m still struggling with the math here - how is the 71 calculated? That’s my average load for the last 7 days?

So Saturday = 48+28 = 76
Friday = 99
Thursday = 68
Wednesday = 39
Tuesday = 58
Monday = 111
Sunday = 0

So 0 + 111 + 58 + 39 + 68 + 99 + 76 = 451 / 7 = 64 - what am I missing?

It is a “Weighted” 7d avg. More recent load is counting higher and older load is counted lower because there is already some recovery.
Don’t break your head over it, these things have proved to be quit usefull.
A general rule in training prescription is to not go over 10% load increase per week and to take a recovery week every 4 weeks reducing load by around 50%.
It takes about 6 weeks for the chart to settle down because Fitness is 42d weighted avg of your load.
If you want to play around with load values to project the future, you can. Just add planned workouts with a load number and extend your chart in the future. You will get an idea of what load is needed to keep you in the “green”. But always be mindfull for the general rules above and listen to your body.
There’s a learning curve involved here, you will understand things better after training a while and interpreting the results in all the different charts. This not exact science but a bunch of tools to assist you in better planning and training.

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I follow a simple math explained by a coach called Alan Couzens

Works in a cycle of 3 weeks of loads by 1 o de recovery.

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Is there a google spreadsheet with the math on this? Still not following.

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Not immediately a formula to put in a spreadsheet but this is a readable format of the calculation:
Today’s CTL = Yesterday’s CTL + (Today’s TSS - Yesterday’s CTL)/Time Constant

where Time Constant is in days. Default values of 42 days for CTL and 3-10 days for ATL (7 is used as a default)

ATL is same formula as CTL, simply use ATL instead and the relevant TC.

Today’s TSB = Yesterday’s CTL - Yesterday’s ATL

Don’t forget that to calculate your needed daily load to remain in the green will need a recalculation every day because your CTL changes everyday…
A TSS of 60 has a different outcome if your CTL is 40 or 120.

Found a reputable source:
https://help.trainingpeaks.com/hc/en-us/sections/205644448-Glossary-of-Terms

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Was going to post this link:

ok thanks for all the links - still want to see the math such that a 5 year old could do it.

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I found a spreadsheet but it does not do the weighting.

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Just use the formula that @MedTechCD provided, plug it into your own GoogleSpreadSheet / Excel and fill in the blanks.

(Note: This is app code)
let newAtl = prevAtl + (TodayTSS - prevAtl)/7
let newCtl = prevCtl + (TodayTSS - prevCtl)/42

eg:
Date | TodayCTL | TodayATL | TodayTSS | NewATL | newCTL

copy your current CTL/ATL into it and then the relevent formulas in NewATL/CTL

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I’m busy putting one together, will share the link once done.

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  • ATL = (ATLyesterday)(e(-1/k))+ (TSStoday)(1-e(-1/k))
  • CTL = (CTLyesterday)(e(-1/k))+ (TSStoday)(1-e(-1/k))
  • TSB = CTL - ATL
  • K= Time constant (7 for ATL and 42 for CTL)
    e = 2.71828
    ATL = fatigue
    CTL = fitness

ok I think I got it…

here is an unnecessarily complicated spreadsheet on how to do that math but it shows the steps.

Thinking about this a bit further, the super stupid easy answer is to

Fatigue = take yesterday’s fatigue number x 0.8669 + today’s training load x 0.1331

Fitness = take yesterday’s fitness number x 0.9765 + today’s training load x 0.0235

Form = Fitness - Fatigue

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ok now I can actually plan on how much load I need for each day to stay in the optimal zone, knowing that there are certain days I won’t have access to my trainer.

Here’s an example of how TSS, CTL, ATL and TSB are calculated
You can enter your own values in the green columns, as well as TSS.
Then you can calculate CTL, ATL and TSB in the yellow columns based on those figures.
I guess the rounding may result in the -1 delta in some rows.

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I’ve been meddling around w/ this calculation and I was using the same formula as you namely:

let newAtl = prevAtl + (TodayTSS - prevAtl)/7
let newCtl = prevCtl + (TodayTSS - prevCtl)/42

BUt when I compare the data with that from intervals.icu’s wellness API endpoint, I get some differing number (rounding delta of 1 or -1 from my calculation and that of intervals.icu)

It took some digging, but the formula from @JASON_C_WILLIAMS

  • ATL = (ATLyesterday)(e(-1/k))+ (TSStoday)(1-e(-1/k))
  • CTL = (CTLyesterday)(e(-1/k))+ (TSStoday)(1-e(-1/k))

Was the key to consolidating the numbers from my own calculation and that of intervals.icu (now they match)

Somehow, the formula used by @david for intervals.icu and that @JASON_C_WILLIAMS got is different from that of TP’s article you linked. https://help.trainingpeaks.com/hc/en-us/articles/204071884-Fitness-CTL-

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Metrics, in general would be the same as using a power meter for testing; always use the same one to ensure consistency.

Strava uses 25s EWMA for “NP”, TrainingPeaks uses 30s EWMA, and (I think) Xert something different, all use different methods to calculate training load.

In your case, Form from different analytical tools uses different methods based on yesterday or today. It’s important to avoid comparing between methods as there will be a different.

I have been using WKO4 and WKO5, and still use it. I don’t try compare it to Intervals, but rather use the best of both applications.

Trends are more important that the absolute value. So the Fitness, Fatigue and Form should rise and drop at a similar rate…

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I’m going to repeat Jason’s feature request. My goal is to keep my form in the optimal training zone -10 to -30. For each day I would like to see how much load I still need to generate today to keep my form below -10 and above -30. I don’t want to make my own spreadsheet. I want intervals.icu to show me exactly what that magic pair of numbers is.

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There are easier ways to get optimised training done, and looking at the numbers can be too complicated, and unnecessary. A better way to do it, where I have seen progress in every cyclists I’ve given workouts to, and that have followed the plan (not 100% compliant, but at least >80%) have shown improvements in performance.

Over a 4 week period, aka traditional periodization, there would be an increase in either:

  • the workout duration at the same power, or
  • the power for the same duration.

If I see them struggling, based on RPE and Feel, I would dial back the intensity a few watts, or perhaps they need a longer recovery. Otherwise I encourage them to not use ERG mode and ride to feel. If they feel strong, go a little harder, eg. the 8m intervals, they can go at 95% if they feel sluggish or up to 105% if they’re feeling really strong.

Here’s view of one person’s calendar, taken at random (they’re moving into Base2 next week):

  • I try keep their ramp rate below 5, unless they are truly a good responder to fatigue.
  • You’ll see the week’s form shows green as I’m not worried about their day to day scores.
  • You’ll also notice the progression is focused on increases in weekly workouts.
    While I personally start on a Monday, because I train in the afternoon (weekdays) and morning (weekends), I try encourage them to have a reserve day. In this case, it’s a Friday. If work/life prevents them from following the plan, they have a day in reserve. If they want to add another ride, the rule is simple: keep it easy. The Free ride on Sunday is difficult (many times they want to race up the hill, because others are doing it, and they want to see how their performance is improving). That’s that the free ride is for… let them have fun, but keep the intensity lower than normal for the rest of the ride.

Hope this helps.

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