measuring speed loss from hip instability

I've been working on making my hips more stable in my V1 skate technique,
since Zachary Caldwell pointed out my problem with that. In three sessions
of practicing stable hips and some time-trial measurements both with and
without poles, it looks like my "wiggly" hips were costing me a speed loss
of more than 4%

I've practiced so that now I can choose use either wiggling hips or stable
hips when I skate either no-poles or V1 (offset) poling. I'd guess that
I'll see larger gains in speed as I more fully integrate stable hips with
all the other parts of my skating motion, and as I develop slightly
different specific muscles for it. So thanks a lot, Zach -- 4% is a pretty
nice gain for just three practice sessions.

Seems like a key driver of me wiggling my hips was to have a quiet _head_
position. Stable hips plus torso-swing yields head moving from side-to-side
relative to the center-line of overall forward motion on the ground. This
head motion is easily seen in videos of the V1 skate of Swenson and
Alsgaard. But a quiet head _feels_ better to me, so I was
"counter-swinging" my hips so that in combination with my torso-swing, the
side-to-side motion cancelled out up at the level of my head -- and a quiet
head is a pleasant way for me to experience the world.

So now I'm practicing watching out for that pleasant head-quietness -- and
recognizing it as a _warning_ of 4% speed loss -- a signal to get my hips
stable, facing square in my line of overall forward motion.

day 1: Skated no poles on flat terrain with hands on top of pelvis side
"points", good position to learn sensitivity to both hip-rotation and
tension in the TrA muscle. Practiced switching between wiggly hips and
stable-square hips. Thought about the hip staying out there to the side,
helping my leg push out to the side. Thought about opening hips, keeping my
knee pointed out in line with the ski, not dropping inward.

day 2: Skated with poles V1 up hill of 8-11% grade on Jenex 6400 (faster)
rollerskis. Results:
-- V1 skate, wiggly hips = 5:59
-- V1 skate, stable-square hips = 5:42

day 3: Skated gentle uphill with no poles on Jenex 830 (slower) rollerskis.
Held a ski pole horizontally across the front of my hips/pelvis. Observed
whether the ski pole rotated side-to-side or stayed square while I skated.
Found that I was pretty good at controlling selection of one mode or the
other. Time-trail results:
-- No-poles skate, rotating hips = 3:23
-- No-poles skate, square hips = 3:14

I was using torso-swing in all cases, so this was in no way a test of Quiet
Upper Body, only Quiet Hips.

With early results like that, I think I'll put lots more work into this "hip
stability" thing.

Ken