Animal Athletes -- Beyond Mascots And Slogans You'll Find Performance Humans Only Dream Of

FLOAT LIKE A BUTTERFLY, of course. Sting like a bee, sure. But how about run like an antelope? Endure like a rattlesnake? Soar like a bar-headed goose?

Set aside those old slogans in the sporting world that appeal to the animal in athletes. Enter the inner realm of comparative physiology, where researchers investigate - and appreciate - the athletes in the animal kingdom.

"One of the reasons that we study animals as athletes is that they represents the limits of how the system can work," says Kevin Conley, an associate professor of radiology and of physiology & biophysics at the University of Washington Medical School.

Among Conley's favorite examples is the antelope. Not just any antelope, but the North American pronghorn antelope, which we might see while driving through eastern Montana or Wyoming. "It's one of the most aerobic species on land," he says.

For good reason. African horned mammals are found in herds of thousands, which can withstand the loss of a few to lions or cheetahs. But their North American counterparts travel in herds of only three or four that can be decimated if one or two are lost to predators. To survive, they have developed an incredible endurance.

To measure endurance, or aerobic capacity, researchers look at maximum oxygen consumption (VO2 max), measuring the amount of oxygen (in ccs) used per kilogram of bodyweight. For a normal human being 25 to 40, it's about 40ccs. Elite runners, cross-country skiers and high-altitude climbers might be 75 to 85 - a capacity they're mostly born with.

Race horses have a very high VO2 max, 150ccs, primarily because they have hearts as big as basketballs that can pump more oxygen-rich blood throughout their system.

But the North American pronghorn antelope's VO2 max is 300ccs. And it has a high anaerobic threshold, the ability to exercise for extended periods at a high percentage of their maximum. "They can run at 55 miles an hour - for hours," says Robert Schoene, also a UW professor of medicine and director of the exercise laboratory at the UW Medical Center-Roosevelt and at Harborview.

Researchers find this out about antelopes in the same way they test humans: by training them to run on treadmills, strapping on masks and measuring oxygen in and oxygen out plus oxygen in the blood.

As with humans in competition, though, aerobic capacity isn't everything. Wolves don't have tremendous VO2 max or endurance but still are the pronghorn's biggest predator because they travel in packs and are cagey hunters.

Size likewise is not essential. The highest VO2 max measured in a mammal is 400ccs - in a blind shrew that weighs just a couple of grams. "It just burrows constantly," Schoene says, "and it has huge back and shoulder and chest muscles, relative to their bodies."

Schoene marvels at birds that migrate at extreme altitude, such as the bar-headed goose, which summers on the Tibetan plateau and winters on the beaches of India. Which means they must fly over the Himalayas, at 28,000 to 30,000 feet. "They don't acclimatize," Schoene says, "they just get off their butts on the beach and fly." Their heart, muscle and lung adaptations are similar to how humans adjust to altitude, but over time. Understanding how these geese adapt so quickly helps researchers learn more about hypoxia, or lack of oxygen in the blood, whether from high-altitude mountain climbing or from emphysema or heart failure.

The rattlesnake is one of Conley's favorites: It can rattle between 25 and 100 times per second (depending on the temperature) for hours at a time. That tail is made up of just one type of fiber, unlike humans who have two kinds, fast-twitch, predominant in explosive athletes, and slow-twitch, that prevail in endurance specialists. Yet the rattling tail combines both properties, like a sprinter and marathoner rolled into one.

"It's energetically costly, but economical," Conley says.

What can we learn from studying a rattlesnake's tail? Efficiency, for one: Researchers are careful to take good care of their rattlers, Conley says.

"It's enough of a hassle to go get them and keep them here."

Molly Martin is assistant editor of Pacific Northwest magazine. ------------------------------- NOTEBOOK

Research update

-- Children as young as 7 and 8 can significantly increase bone mass through a brief, specific weekly exercise routine that may help them "bank" extra bone to fight osteoporosis in adulthood, found a pilot study at Oregon State University. The children were asked to jump off 2-foot boxes 100 times, three times a week, for seven months. They had 5 percent more bone mass than classmates stretched and did nonimpact exercise. That translates into a 30-percent decrease in the risk of a hip fracture at adulthood, says Christine Snow, director of the Bone Research Laboratory at OSU. Similar results might lead to simple changes in school physical-education programs.

-- Researchers at the University of Arizona have evidence for what many already know: Regular exercise can help us sleep. People who walked more than six blocks a day reported 33 percent fewer sleep disturbances than folks who walked less. If that walk was brisk, sleep problems were cut in half. Researchers speculate that exercise increases the body's core temperature, lulling us to sleep like after a warm bath. One exception: Women who got regular exercise, vigorous on weekends, reported double the sleep disorders. Researchers speculate that they were often exercising late in the evening, which can be detrimental to sleep.

-- Remember the old saying that if you take medication, a cold will last a week and if you don't it'll last seven days? The same may be true for low back pain. A study at Group Health supported by the federal Agency for Health Care Policy and Research found no difference in outcomes among patients who were treated by either chiropractic manipulation or the McKenzie method of physical therapy or were given a booklet and not treated.