What is ultimately the most efficient body structure of a fast runner?

why is it more efficient to have a short midsection?

big fat guy with short legs, of course.

why small feet?

Very thin, short torso and long legs

Yes but there are no free lunches.

Smaller torso means smaller internal organs, reduced vo2max.

So yes - more efficient - but not necessarily faster.

A wide rib cage sitting on a pair of long legs. All lungs and legs, nothing else needed.

One thing that's underappreciated about geb is that his legs are actually pretty long, his torso is insanely short though. He's not lacking for lung capacity because his rib cage is relatively wide.

However, the distribution of calf muscle is better in the kenyans than the ethiopians. You want the muscle mass closer to the knee joint so it swings less.

First Year Coach wrote:

A wide rib cage sitting on a pair of long legs. All lungs and legs, nothing else needed.

How should the long legs be proportioned? I.e. how should the length of the shin relate to the length of the femur?

According to "Biomechanics of running economy" by Anderson (1996) and "Factors affecting running economy in trained distance runners" by Saunders et al. (2004):

Height- average of slightly smaller than average for males and slightly greater than average for females

Ponderal index- high and ectomorphic or mesomorphic physique

Body fat- low

Leg morphology- mass distributed closer to the hip joint

Pelvis- narrow

Feet- Smaller than average

leg proportions wrote:

How should the long legs be proportioned? I.e. how should the length of the shin relate to the length of the femur?

In "Physiological characteristics of the best Eritrean runners--exceptional running economy," Lucia et al. (2006) compared elite male Eritrean and Spanish runners. The two groups had a similar VO2max but the Eritrean runners had significantly better running economy than the Spanish runners. The Eritrean runners had a significantly lower BMI, maximal calf circumference, and significantly greater lower leg length compared to the Spanish runners.

Should I quit running because I wear size 14 shoes? Can someone explain the small foot advantage?

Also, I heard from someone at a race that the perfect height to weight ratio was 2 pounds per inch. The guy was rather old, so it might be an outdated standard, but curious to see if there's any truth to that.

GK wrote:

Should I quit running because I wear size 14 shoes? Can someone explain the small foot advantage?

I understood that smaller feet mean less time contacting the ground. And, I thought I heard somewhere that short toes specifically correlated with faster running - the foot toes off more efficiently. I don't have a cite for that, though.

Most of the recent Boston Marathon winners were 5'7 and 130 pounds.

Average elite female runner is 5'5 and weighs 117 pounds.

An ideal runner has a bmi of 19-20, is an average height (female), or slightly below average height (male), and 10% percentile in weight. The ideal runner has small feet, long legs, small calves and a small upper body with most of the weight centered near the center of gravity around the hips and thighs. Elite runners are actually only moderately flexible as too much flexibility can harm performance.

http://books.google.com/books?id=wAa9qq9kbncC&pg=PA180&lpg=PA180&dq=average+marathon+winner+170+cm&source=bl&ots=cxk5AU5leD&sig=s_brBG_1Q_P1ho-VsQUwBTTl0ao&hl=en&sa=X&ei=WVDjT7HSPI6W8gTDnr2GCA&ved=0CEkQ6AEwBA#v=onepage&q&f=false

darkwave wrote:

GK wrote:

Should I quit running because I wear size 14 shoes? Can someone explain the small foot advantage?

I understood that smaller feet mean less time contacting the ground. And, I thought I heard somewhere that short toes specifically correlated with faster running - the foot toes off more efficiently. I don't have a cite for that, though.

Would there also be an advantage having less weight at the end of your leg for runners with smaller feet? Kinda like wearing the lightest shoe possible to get the most speed.

There are two near-perfect body types for a fast runner, depending upon if one wishes to run extremely fast over short distances and unimaginably fast over longer ones:

http://en.wikipedia.org/wiki/Pronghorn

or unimaginably fast over short distances and not-so-much over longer ones:

http://en.wikipedia.org/wiki/Cheetah

Perhaps by efficiency you are excluding speed from the equation, but if you are including speed as a factor, then the most efficient structure also depends on the distance.

For example, for shorter distances, greater height, as long as it's not too great, is less of an issue or has offsetting benefits. Or greater weight from more powerful and explosive muscles has offsetting benefits in shorter distances, etc.

joho wrote:

darkwave wrote:

I understood that smaller feet mean less time contacting the ground. And, I thought I heard somewhere that short toes specifically correlated with faster running - the foot toes off more efficiently. I don't have a cite for that, though.

Would there also be an advantage having less weight at the end of your leg for runners with smaller feet? Kinda like wearing the lightest shoe possible to get the most speed.

yes, your entire leg rotates around the hip joint. when rotating something, it's easiest to distribute weight close to the axis. harder to move if it's out on the end. big heavy feet are a disadvantage. That's why some exercise phys types think the carbon blades are an unfair advantage for Pistorius.(Truth is, it'd be a bigger advantage in a longer race)

Additionally a bigger foot is a longer lever and so requires bulkier calf muscle to push off. And as noted earlier, smaller calf muscle correlates with better efficiency.

I actually fit the description somewhat well!

5'11

30x32 pant size

size 10 shoes

Mr. Battery wrote:

I actually fit the description somewhat well!

5'11

30x32 pant size

size 10 shoes

My guess is that 90% of the folks on here do - or at least did in their glory days.

First Year Coach wrote:

yes, your entire leg rotates around the hip joint. when rotating something, it's easiest to distribute weight close to the axis. harder to move if it's out on the end. big heavy feet are a disadvantage. That's why some exercise phys types think the carbon blades are an unfair advantage for Pistorius.(Truth is, it'd be a bigger advantage in a longer race)

Additionally a bigger foot is a longer lever and so requires bulkier calf muscle to push off. And as noted earlier, smaller calf muscle correlates with better efficiency.

One thing to look at is all of the fastest animals, like a horse, gazelle, cheetah, greyhound, etc. They have small feet compared to their leg size (effectively running on their toes) and the larger muscles powering the legs are closer to the point of rotation (shoulder/hip) compared to a human.

Twould explain why I have bigger calves than most runners, but I don't think my feet contact the ground longer. Maybe if I were stupid and ran on my heels, but I'm more of a forefoot guy. I don't plan on winning the olympics, so not a big deal. Interesting topic though. It's always fun to see people at a race that appear too short, too tall, or too fat..., but somehow are super fast.