training question

Charlie Pendejo said:

David Geesaman said:

Running at a sprint tends to put a lot less impact through
the joints than jogging.

I do understand your point about stride rate and smoothness. But
(quoting from _Run Strong_, Human Kinetics, 2005, Jack Youngren's
chapter "Stride Mechanics"😉:

It's counterintuitive, but I think the reason for this is the shorter
ground contact time when you turn over at those really high speeds.

Sure, the total change in downward velocity is less, because you're not
falling as far, but time window in which that change of pace occurs is
also much smaller.

Quoted message said:

-- snip --
The main impact force encountered on landing is the vertical ground
reaction force. This is the bone-jarring component of the force of
impact that is transmitted straight up the limb.

Well sort of, except that the impact needn't be "transmitted straight up
the limb". The achilles tendon/calf is more likely to absorb some of it when
running fast.

Quoted message said:

-- snip --
Impact forces are greater at faster speeds and are absorbed through
a smaller area of the foot because a forefoot strike becomes more
prevalent. Stresses on the Achilles tendon are much greater [...]

Yep. One of the problems with running "correctly" is that it does place
more stress on the bones of the foot. This is only a problem for people
who insist on wearing very light shoes on hard training surfaces.

Cheers
--
Donovan Rebbechi
http://pegasus.rutgers.edu/~elflord/

Donovan Rebbechi said:

the impact needn't be "transmitted straight up the limb". The achilles
tendon/calf is more likely to absorb some of it when running fast.

Yeah, and then spring back to provide some of the propulsive force.
That's the bit I couldn't find earlier:

-- snip --
In fact, it has been suggested that at faster running speeds, the
muscles of the calf provide minimal work and the majority of the
propulsive force imparted by the foot comes from energy stored and
released by the Achilles tendon.
-- snip --

"Charlie Pendejo" <[email hidden]>

Quoted message said:

-- snip --
In fact, it has been suggested that at faster running speeds, the
muscles of the calf provide minimal work and the majority of the
propulsive force imparted by the foot comes from energy stored and
released by the Achilles tendon.
-- snip --

.....or Snap! Other tendons in the leg also supply that all-important
rubber-band power. I believe we are unique among primates in the
springiness department.

Many good uphill runners rarely touch their heels to the ground when
climbing at race effort. Springiness is next to Godliness.

It also may explain the counterintuitive fact that the very fastest distance
runners often have the thinnest calves.

-- Dan

I would also say the faster the run the more likely the potential for
injury. Run fast only after running for a while.

"TenKBabe" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I'm for it! said:

Quoted message said:

Well, vaguely I want to improve my cardiovascular system.>

Then Long Slow Distance will do it, and with minimal chance of injury.
Nothing sheds pounds like a long slow run.

A long fast run will burn more calories and therefore encourage more
weight loss than a long slow run. The problem is that you can't do
these as often. They require some amount of recovery with a day off or
an easy run.

tkb

"TheVicar" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"TenKBabe" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I'm for it! said:

>Well, vaguely I want to improve my cardiovascular system.>

Then Long Slow Distance will do it, and with minimal chance of injury.
Nothing sheds pounds like a long slow run.

A long fast run will burn more calories and therefore encourage more
weight loss than a long slow run. The problem is that you can't do
these as often. They require some amount of recovery with a day off or
an easy run.

this sort of complete explanation is really not encouraged here. We've
been told LSD burns more fat for years now and we've blindly accepted
this. applying the whole story to our tiny little minds is not going to
help us. as it is some of us have heads that are too heavy for our puny
shoulders to hold up so dont go putting anymore information in them.

It does not matter what you "burn" only that you create an energy
deficit.

Quoted message said:

i'm still at 0 miles as i ramp up at no more than 10% mileage per week for
that last 5 years.

Quoted message said:

tkb

"Charlie Pendejo" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

David Geesaman said:

Running at a sprint tends to put a lot less impact through
the joints than jogging.

I do understand your point about stride rate and smoothness. But
(quoting from _Run Strong_, Human Kinetics, 2005, Jack Youngren's
chapter "Stride Mechanics"😉:

<Good stuff snipped>

Well, that's the reason I inserted the word 'tends'.

There are a couple major practical things to consider as well that I
feel suggest the normal runner should be more concerned with their jogging
form than anything else:

- Most recreational/beginning runners cannot maintain a very fast pace
for very long. Jogging however is much more sustainable, and the cumulative
damage is much greater. As well, the jogging is often done on harder
surfaces.

- Sprint vs. fast stride - Using the word sprint is a bit of
overstatement - more accurately I feel that running at a smooth 90% stride
("wind sprint" or "strider"😉 is the naturally efficient running form I had
in mind.

- The source in question is not clear on what kind of sprinters were
being studied. (Although I'd venture to say elite sprinters are far more
likely to be studied than recreational runners sprinting). Just based on
the sound of footsteps, high-level power sprinters do have a very high
impact footstrike. Some guys sound like they're ripping the rubber off the
track, and their spike marks don't deny the possibility. Their propulsive
forces are clearly a level above the norm. I think if that's the kind of
data in front of us, we have to be realistic in that normal runners can't
generate that kind of loading.

Dave