Inconsistent CTL ("fitness")

Either I’m doing something wrong or there’s a bug. I cycle and run, so I wanted to create separate CTL (“fitness”) values for each sport (bike is orange, run is green, total is purple). My understanding is that “fitness” is just a weighted 42d average of training load, but my numbers rarely add up. Looking at the 42d plot you can see that fitness (blue) doesn’t match the purple line, which is supposed to be 42d weighted training load (the same as fitness unless I’m misunderstanding).

42d view

How I set up the TL graph

Another problem I’m seeing is that depending on which view I have (for example: 6 mos vs 3 mos vs 42d), the purple/orange training loads are being calculated differently and the value changes.



Have I done something wrong here or is this a bug?


To calculate CTL completely accurately you need to consider your complete history because some of your past training load is always present. For the built in fitness and fatigue numbers does this and stores the results.

The “Fitness Average” function includes the 84 days before the start of the chart in its calculation, not your complete history. So it will be a little lower and more so at the start of the chart. I have just changed this to 184 days and the starting CTL is now within 1 of the “complete history” number for me. The charts will take a bit longer to load now but I think it’s ok.

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Thank you!! My numbers are matching now, this helps tremendously as a multi-sport athlete :pray:

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