Re: Even More Mechanics

Steve Hansen said:

Daniel said:

1.) First a little about "shorter step": When I *started* running with a
more rapid turnover (from a loping 120 to 140 footfalls per minute to the
ChiRunning recommended 180), yes I was taking (even) shorter steps. But I
don't think the goal is to take short steps, the goal is to have rapid and
even turnover.

I think the goal is to move rapidly forward, with a minimum of
energy expended, and a minimum possibility of injury. Or,
alternatively, to move as rapidly forward as possible, and
with a minimum possibility of injury.

Ah, you'r right of course. I should have said something like "the reason
for taking what seems like short steps in the beginning is to have rapid
and even turnover, which in turn will be a way to move forward..." (what
you said).

Quoted message said:

Experience has shown that a higher turnover contributes to
this goal, but I don't think it is a goal in itself.

Quoted message said:

My unsupported hunch: If my *form* basically stays the same at different
speeds, I will be less prone to injury. For me, that's the real sales
"hook" to the rapid-cadence ChiRunning school of thought: Injury Free
(*not* the gravity-moves-you thing).

I think I agree. Injury-free is certainly one of my goals.

Quoted message said:

2.) And an aside about hills: Hill running form *is* different. I tend to
tiptoe up hills with very short stride length, as short as necessary to
keep my heart rate/breathing tolerable.

I really don't know. I live in Florida. There are no hills, here.

There's a documentary about the Badwater ultramarathon ("Running on the
sun"😉 that has a runner from Florida training on the biggest "hills" he can
find: freeway overpass!

Quoted message said:

Quoted message said:

3.) Question: Where is my center of gravity when my foot comes down?

I am, historically, very prone to injury. My right knee/ankle angles
are not quite right, due to having broken a leg about 40 years ago.

I know that, when I move efficiently, with minimum deceleration and
minimum vertical motions, I also avoid injury. I know that when I
forget about form, and let myself "pound" for a few miles, I am
sore for the next couple of days.

Quoted message said:

Which makes me wonder: is it possible that my body is flexible enough to
allow ( . . . allow *what*? my center of gravity? some imaginary point
behind my sternum?) my upper body to sail along with minimal vertical
displacement while my feet/legs first catch/decelerate/shorten, then
support/stop/dorsiflex, then push/accelerate/lengthen -- cycle after cycle
after cycle?

Your center-of-gravity (COG) is closer to your belly-button than
your sternum.

But the idea of using your inertia is right. If you use
your flexibility to maintain inertia, you can be more efficient.

You maintain inertia, and avoid wasting energy, in two ways.
One, by minimizing vertical movement (of your COG). Vertical
movement costs energy at every step. Second, by avoiding
horizontal deceleration, because braking/pushing costs energy
at every step.

The cycle consists of providing an 'impulse' or 'push' that
equals what is needed to maintain forward speed and keep from
falling. Extra vertical motion is just wasted energy, and
requires a larger impulse. Extra braking/pushing is just
wasted energy, and requires a larger impulse.

By minimizing the required impulse, and using more impulses
per-minute, you minimize the pounding and the injuries.

By minimizing the wasted energy, you can also go faster/farther
for the same energy.

Steve

Thanks!
--
Daniel
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