Chronic Load

I'm a bit baffled with this one: looks redundant to me.

It says(and I verified too with my own data) that it follows the bottom of the acute load green area. So I'm not sure which one is based out of the other one but I don't see the added value there at all.  

It's the equivalent of the long known CTL(chronic training load,first spotted years ago in TrainingPeaks)

Althought legitimate, Garmin seems sometimes a bit desperate to throw in a new thing(even if not so new) to keep us interested :)

patrickd123 said:

I don't see the added value there at all

Maybe this article will help. Essentially it is the ratio of acute load vs chronic load that defines the 0.8-1.3 sweet spot where, according to research, the risk of injury is reduced

www.firstbeat.com/.../

patrickd123 said:

It's the equivalent of the long known CTL

Kind of, yes. CTL, unfortunately called "Fitness" by TrainingPeaks, is a little bit longer term (42 days vs 28) and also decays with time.

The big different is that CTL is based on TSS, which is based on external output, vs Garmin's training load which is based on the metabolic cost.

Although the pace/power data used for TSS/rTSS are the same, they are direct input to the TP metrics, whereas they are used in combination with HR data kinetics and movement dynamics data in Garmin through a model to estimate the internal metabolic cost. This gives you a more individualized result. The estimation of EPOC is not super accurate (Garmin doesn't publish it per se, but from the data I see in their white papers, I estimate it is around 10-15%).

So you have a trade off: more accurate vs less individualized for TSS based metrics. Both methods are valid.

help.trainingpeaks.com/.../204071884-Fitness-CTL-

That's part of the current beta. 

Oh, you pointed to look at the right direction: https://gadgetsandwearables.com/2023/03/28/garmin-fenix-7-wrist-based-running-dynamics/

Thanks

Thanks for the thorough and pertinent answer. I guess it will all suddenly make sense when "the missing link" (the Training Load Ratio) will be released, which I read is imminent!

Imminent, well ... this quarter.