bookofjoe

Humans may be capable of running 40mph (Usain Bolt's top end is 27mph)

A paper published this month in the Journal of Applied Physiology (JAP) analyzed the various constraints on human running speed and concluded we're nowhere near what's possible.

Here's Telegraph (UK) science correspondent Richard Alleyne's January 25, 2010 story about the study's implications.

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Man biologically capable of running at 40 mph

A man able to run at 40mph would cross the finishing line in a 100 metre sprint race in 6.67 seconds - just as Olympic and world champion Bolt reached the 60 metre mark.

Scientists calculated the ultimate possible running speed by calculating the quickest rate at which muscles in the body can biologically move.

Previous studies have suggested the main hindrance to speed is that our limbs can only take a certain amount of force when they strike the ground but the new research suggests it's the contraction of our muscles that holds the key.

Dr Matthew Bundle, a biomechanics expert at Wyoming University, said muscle contraction speeds would permit running speeds of 35 to 40 miles per hour - and conceivably faster.

The researchers used a high-speed treadmill capable of attaining speeds greater than 40mph which could record precise measurements of the forces applied to the surface with each footfall. They also had subjects' perform at high speeds in different gaits.

The ground forces applied while hopping on one leg at top speed exceeded those applied during top-speed forward running by 30 per cent or more, according to the findings published in the Journal of Applied Physiology.

And the forces generated by the active muscles within the limb were roughly 1.5 to 2 times greater in the one-legged hopping gait by the subjects.

Dr Bundle and colleagues said their work showed running speed limits are set by the speed limits of the muscle fibres themselves, with fibre speeds setting the limit on how quickly the runner's limb can apply force to the running surface.

The Olympic gold medallist Usain Bolt has clocked nearly 28 mph in the 100-metre sprint. But this is dwarfed by lions that can run at 50mph when chasing prey and cheetahs that can reach 70mph.

Prof Peter Weyand, a physiologist and co-researcher at Southern Methodist University in Dallas, said: "The prevailing view that speed is limited by the force with which the limbs can strike the running surface is an eminently reasonable one.

"If one considers that elite sprinters can apply peak forces of 800 to 1,000 pounds with a single limb during each sprinting step, it's easy to believe that runners are probably operating at or near the force limits of their muscles and limbs.

"However, our new data clearly show that this is not the case. Despite how large the running forces can be, we found that the limbs are capable of applying much greater ground forces than those present during top-speed forward running."

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Here's the abstract of the paper published in JAP.

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The biological limits to running speed are imposed from the ground up

Running speed is limited by a mechanical interaction between the stance and swing phases of the stride. Here, we tested whether stance phase limitations are imposed by ground force maximums or foot-ground contact time minimums. We selected one-legged hopping and backward running as experimental contrasts to forward running, and had seven athletic subjects complete progressive discontinuous treadmill tests to failure to determine their top speeds in each of the three gaits. Vertical ground reaction forces (in body weights; W_b) and periods of ground force application (T_c; s) were measured using a custom, high-speed force treadmill. At top speed, we found that both the stance-averaged (F_avg) and peak (F_peak) vertical forces applied to the treadmill surface during one-legged hopping exceeded those applied during forward running by more than one-half of the body's weight [F_avg = 2.71 ± 0.15 vs. 2.08 ± 0.07 Wb; F_peak = 4.20 ± 0.24 vs. 3.62 ± 0.24 W_b±sem] and that hopping periods of force application were significantly longer [T_c = 0.160 ± 0.006 vs. 0.108 ± 0.004 s]. Next, we found that the periods of ground force application at top backward and forward running speeds were nearly identical, agreeing to within an average of 0.006 s [T_c = 0.116 ± 0.004 s vs. 0.110 ± 0.005 s]. We conclude that the stance phase limit to running speed is imposed, not by the maximum forces that the limbs can apply to the ground, but rather by the minimum time needed to apply the large, mass-specific forces necessary.

Coffin Cigarette Case

"Who says negative reinforcement

doesn't work?"

[via xiankankan, Sweet Station and New Idea Homepage]

Best dust jacket of the year

Above, it's for the American edition of Steven Amsterdam's upcoming (February 2, 2010) novel, "Things We Didn't See Coming."

Bee Glass Brush

7" tall.

$7.99.

'Yours, Mine, Ours' — by Sebastian Martorana

Bath towels carved from marble,

part of his current show "Uncommissioned Memorials,"

up through February 6, 2010 at Washington, D.C.'s Irvine Contemporary Gallery.

The heaviest one (above and below)

weighs 140 pounds.

[via Jessica Dawson and the Washington Post]

Nouveautés Bonnet de bain

See, French isn't all that hard after all.

Let's do some more: "Remuez vous les méninges. Enfin un bonnet de bain intelligent. Silicone. Taille unique."

€15.75.

[via swissmiss, Inspire me, now! and m,appeal]

Michael Pollan's 10 Food Rules to take to the market

The author's rules of thumb for those who can't be bothered to read his articles or books.

1. Don't buy anything your great grandmother wouldn't recognize as food.

2. Avoid products with ingredients that cannot be found in an ordinary pantry.

3. Don't buy anything that lists sugar in its first three ingredients.

4. Shop the peripheries of the supermarket and stay away from the middle.

5. If it came from a plant, buy it. If it was made in a plant, pass it by.

6. If it says lite, low-fat, or non-fat on the package, put it down.

7. Avoid food that is pretending to be something it is not.

8. Foods making health claims on the package are not foods you want to buy.

9. Avoid food that is advertised on television.

10. Get out of the supermarket. Look to farmer's markets.

Stress Croissant

"A very realistic-looking croissant-shaped sponge."

 

"It even smells like a freshly baked bun."

 

"Use it as a stress ball or a wrist rest."

$11.45.