*Think of a 90k DP-fest like Mora:
would you rather depend on core/torso or arm/back muscles? *Of course,
no one is doing short, truly explosive strokes every time; one could't
last long that way.

This clarifies where I'm confused. I've always thought of, even the
old, slow, double-pole as mostly depending on abs. The different for
me, when I try a shorter explosive style, is that less of my body
weight comes into play. In the old-school style, I think of falling
on the pole, and then continue that feeling of body weight on the
poles, while I add an ab crunch. New style feels like all ab crunch
and lat pull-down.

In teaching intermediate skiers, it has still seemed productive to
encourage them to feel the body weight sensation...

Jon