Watching Their Steps

All told, we were 20 world-class distance runners, Olympic marathon champion Frank Shorter and the late Steve Prefontaine among us. We were gathered on a Dallas winter day 16 months ago, not at a track or a cornstubbled cross-country course, but in the warmth of the Willow Bend Polo Club, to be spoken to intently over prime sirloin, to have our suspicions allayed. Here were scientists—blood men, muscle men, mind men, the best in the country—asking permission to photograph, probe, exhaust, bleed and work all manner of other discomforts upon us. All, of course, in the interests of science.

We had a right to be suspicious. We knew that research had been going on for decades, the literature advancing glacially along the library shelves, and still no one had explained why Jesse Owens or Bob Hayes or Valery Borzov could run 100 meters faster than anyone else or why Shorter dominated the marathon. In brief, exactly what factors of blood and nerve and chemistry allow one human muscle to be faster, stronger or more enduring than another?

As science had not supplied much of an answer to this question, coaching knowledge developed through trial and error. The sport of track and field has been advanced by stubborn crackpots trying such deviant methods as flopping backward over the high-jump bar or running 250 miles per week in training. Athletes, the beneficiaries of such progress, tend to identify with the crackpots.

Many of us were reluctant, too, because science seldom had acted in our interests. Blood had been taken from some of us in 1971 under the pretense that it was part of the U.S. Olympic Committee exam necessary to enter the Pan-American Games. The last man in line, Marty Liquori, refused, was permitted to join the team anyway, and so proved that the rest of us had been deceived. The blood, it turned out, had gone to a private study, the results of which were never made known to the athletes.

But here was Dr. Mike Pollock, a candid and earnest man, director of the Institute for Aerobics Research, saying we had reason to hope for better. He explained that research had developed ways of isolating and measuring those systems that combine to produce excellence in distance running. Tests of muscle tissue, body composition, cardiovascular function, biomechanical efficiency and psychological traits had been developed which seemed to show a complex but decipherable pattern. To prove the usefulness of what had been found, we were to submit to the most comprehensive study ever done on world-class distance runners, then run a six-mile race to compare test results and racing performance.

"Will you be able to predict the winner?" asked Prefontaine.

"We're sure not making any guarantees," said Pollock, "but we'll take a shot at it."

"This I gotta see."

We were to be blooded early. Muscle biopsies were scheduled at the aerobics institute after dinner. "The secrets of differences between athletes reside in their adaptation to training," said Dr. David Costill of the Ball State University Human Performance Laboratory. "The major adaptation, we now think, comes not in the cardiovascular system, as we used to believe, but right in the muscle cells or fibers." Dr. Costill showed slides of muscle tissue taken in previous biopsies, identifying the two kinds of fibers everyone has in voluntary muscle—the "slow twitch," that is used for long-distance work, and the "fast twitch," which contracts more rapidly and is used mainly for short bursts. The fiber types have different chemistries, and the proportion of fast and slow fibers, genetically fixed throughout one's life, was thought to be as much as 90% one way or another. Different sorts of running, Costill had found, exhaust the two types of fibers and their fuel (glycogen) differently. Hard bursts drain it from the fast twitch, long runs from the slow. It stood to reason that sprinters would be endowed with more fast-twitch fibers, distance runners with slow-twitch, and this Costill hoped to confirm.

A point of philosophy seemed unavoidable here. If Costill found that the best distance runners all have at least, say, 70% slow-twitch fibers or that the best sprinters have an equally lopsided share of fast-twitch cells, the results would be applicable at once to helping beginners select which events to train for, but they would also be a blow to that school of exhortation which has held, loudly, that you'll never know how good you are unless you try. It will be possible to know, not that someone will be a champion but that great numbers of eager kids will not.