Life in the fast lane.
No need for expensive running shoes: These animals are adapted for speed.
You're halfway through a race. With muscles aching and chest heaving, you huff and puff toward the finish line. Is there any way to run faster and longer--and feel better while doing it?
You could get some tips by reading every article and watching every program on running stars such as Arturo Barrios Arturo Barrios (born December 12, 1962) is a Mexican long-distance runner, who finished in fifth place in the 10.000 metres at the 1988 Summer Olympics. He is a former world record holder at 10,000 m (27:08.23, set on August 18, 1989). and Greta Waitz. But even their great speeds pale in comparison to some other athletes of the animal world.
Which critter should be your role model? The cheetah cheetah (chē`tə), carnivore of the cat family, Acinonyx jubatus, native to Africa S of the Sahara and SW Asia as far east as India. , the fastest springer in the world? The racehorse racehorse
refers usually to thoroughbred but may also include standardbred, trotter. , bref for speed for almost 400 years?
Guess again. To learn the most about long-distance running, animal physiologist Stan Lindstedt says, check out the pronghorn antelope pronghorn antelope
a fast-moving, wild North American ruminant with hollow core, branched horns which shed their outer sheath each year. Called also Antilocapra americana. .
Never heard of it Never Heard Of It is an unsigned band that has sold over 100,000 copies of their CDs and booked and financed 10 of their own U.S. tours. Including headlining tours of Japan, Mexico, and Europe. ? This three-foot tall mammal is the fastest distance runner on Earth. Though the cheetah might outsprint the pronghorn pronghorn or prongbuck, hoofed herbivorous mammal, Antilocapra americana, of the W United States and N Mexico. Although it is often called the American, or prong-horned, antelope, it does not belong to the true antelope family of Africa on the short track, the big cat would conk out after 30 seconds. The pronghorn would keep going and going. Pronghorns, in fact, can keep up with a car traveling 55 miles per hour for half an hour.
The secret of the pronghorn's success: Compared with cheetahs, racehorses, and humans, pronghorns, are more efficient at taking in an using the oxygen that fuels their bodies, Lindstedt says.
If you've ever worked out, you know your body needs oxygen. You breathe hard to get more of this gas into your lungs. Your heart beats fast as it tries to quickly move the oxygen from your lungs, though your bloodstream, to your muscle cells. That's where the oxygen is ultimately used--in the chemical reactions that give muscle cells the energy they need to contract (and keep you running).
The pronghorn faces the same challenge of getting oxygen to its cells, says Lindstedt. But compared to animals of the same size, thB pronghorn has:
* a bigger windpipe windpipe: see trachea. and bigger lungs to take in oxygen
* more alveoli Alveoli
Small air sacs or cavities in the lung that give the tissue a honeycomb appearance and expand its surface area for the exchange of oxygen and carbon dioxide. , the tiny air sacs air sacs
sacs that communicate with the respiratory, air-filled membranous system in birds and primates.
avian air sacs
there are eight air sacs in the chicken: an unpaired cervical, an unpaired clavicular, a pair of cranial in lungs through which oxygen enters the blood
* a bigger heart to pump more blood through the lungs and to the muscles
* More red blood cells--the components of blood that carry oxygen, and
* more mitochondria--the structures inside muscle (and other) cells where oxygen-dependent, energy-releasing reactions take place.
These traits, says Lindstedt, are examples of adaptations, characteristics that help an animal survive in its environment. Pronghorns with speed-enhancing adaptations are able to outrun out·run
tr.v. out·ran , out·run, out·run·ning, out·runs
a. To run faster than.
b. To escape from: outrun one's creditors.
2. predators and survive. These animals then pass on their traits as the species evolves over time, says Lindstedt.
THE NEED FOR SPEED
Evolution might also explain why cheetahs, racehorses, and humans do not keep up with the antelopes.
To survive, cheetahs only need speed for short distances, says physiologist James Jones. They are adapted to sneak up on prey and pounce with a burst of energy from their powerful hind legs.
Racehorses don't even need their great speed for survival. For the past 400 years or so, their "evolution" has been driven by breeders who want them to win races, not ny the need to survive. Some of the speed-enhancing traits they've developed may even turn out to be harmful to their health (see opposite page).
Finally, says Jones, humans are much slower than these animals because we can afford to be. "Our method of survival is not dependent on being very fast," he says. Instead of running from predators and scampering after prey, we've designed tools and strategies for defense and hunting.
That's not to say individual humans can't get faster, Jones adds. Working out for 20 minutes three times a week will strengthen your heart and muscles, he says. That won't make you as fast as the animals on these pages, but it will make you a more fit human athlete.