Question regarding math behind fitness/fatigue

[Nikolaj_fra_LoberLab]

Can anybody help me explain the formula for calculating the daily fatigue and fitness?
I understand the concept of load, fatigue and fitness.

the question is more practical as it helps me better explain to colleagues and clients.

If i were to make an excel sheet, what would the formula for calculating fatigue and fitness be?

[MedTechCD]

Here´s some ´readable´ interpretation

Calculate Needed Training Load?

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 n…

Search the forum for ´CTL Formula´ for more.

[app4g]

Try this thread:

Calculate Needed Training Load?

I have been trying to keep myself in the green optimal zone for most of December. For me so far though, it’s been a bit of trial and error. I do a Zwift workout and I fall into grey. The next day I add an extra 10 minutes and I squeeze back into green. Is there any way of calculating or estimating how much work I need to do in any given day to keep myself at a given level? I just feel like I’m bouncing around an awful lot.