Rounds, mitts, and the bag
Boxing
Boxing is the most honest feedback loop I have found. Nothing I believe about my guard survives the round where I keep dropping it, and no amount of reading fixes it either: it gets fixed by going again on Tuesday.
It is also the one hour in my week with no laptop in it, which is most of the point.
Carries over
Composure is trainable. Most of what reads as calm when a production load fails the morning of an executive readout is just having been tired and behind before, on purpose, every week.