Looks like a good warmup for a hard lift.
Shadow boxing with 15-20 lb. dumbells seems to be more challenging, and sport specific.
But if it works for him, so be it.
15-20lbs dumbells? Shadow Boxing? I gotta see this, can you vid yourself doing this and host it on youtube please!
I used to do them at 15 pounds - super workout for shoulders, arms, abs, and lower back. Great cardio for fight preparation. I figure a pro could move the poundage up by 5 or so if he had all day to train.
I don’t understand what is outside your frame of reference - the activity, or the poundage?
I have no video capability, but basically you grab the dumbell and start off with stuff like jabs, crosses, uppercuts, and then start working combinations with footwork.