What do the Performance Widget arrows mean?

On the "front page" of the performance widget there are two arrows. One for Fitness, one for Load: https://www.garmin.com/en-US/runningdynamics/#training-status

What do they mean? With me, it says Productive, with a Fitness arrow pointing to the right, and a load arrow pointing upward. Does that mean my fitness is staying level and my load should be increased? Or does it mean that my fitness level is staying put and my load HAS increased? Or does it mean that my load capacity is increasing? Or does it mean that my load is too high and I should decrease it?

I can't find any documentation for those two arrows anywhere. The user manual doesn't mention them wit a single word: http://www8.garmin.com/manuals/webhelp/fenix5x/EN-US/GUID-F5BF67CE-C94E-4842-AE96-A7A05C85B732.html

Firstbeat also has the arrows around their webpage, but they don't tell what they mean either: https://www.firstbeat.com/en/consumer-feature/training-status/