On Tue, 14 Dec 2010 10:10:05 -0800 (PST)
Jon wrote:

_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...

Ab crunch and lat pull down describes it well. In teaching DP, I start
with the basic motion, i.e., ab crunch with knees flexing over ankles
(vs. "sitting on the pot"). Then I move onto how to bring the core
forward in the initiation, using the image of an arrow protruding from
the C-O-G. But not way forward, tho I still give use the "timber!"
exercise to break through the feear about bringing the body forward. In
the newer style, there is normally less fall forward (vs. a sprint); in
fact, I've had a couple of coaches say there is none, just make sure
one's hips are not lagging.

The old DP did, of course, engage the abs first. However, by reaching
out with the arms and using relatively straight legs it took away
everything above the abs, and missed the central biomechanical
advantage of enhancing the push off; everything was spread over the
course of the entire push and glide. It also put a lot of pressure on
skiers' backs. I suspect there are fewer back problems since the
changeover.

Gene