Calculations dash some track records

The wind was blowing too hard. You weren't adjusted to the altitude. You know you could have run faster, but you couldn't measure how much.

Runner-turned-physicist Jonas Mureika has devised a formula to calculate how fast 100-meter-dash times would have been without the effects of wind or altitude.

By leveling the playing field, his calculations suggest a reshuffling of history's fastest races. Frustrated runners may find solace in Mureika's numbers. Even if sprinters don't break records at this year's Olympic Games, researchers say, his model could help sportscasters eke excitement out of disappointing performances in blustery conditions.

Runners have long invoked science to try to figure out how to run faster. Physiologists analyze videos in search of the most efficient stride. Psychologists help athletes stay calm and focused. Trainers tinker with diets and social discipline.

The environment can affect a sprinter's speed just as training and running shoes do, though, especially for the 100-meter dash - a straight shot down the track. If wind at the runners' backs blows faster than 2 meters per second, record-breaking runs aren't official. But wind less than that can push a runner forward (or pull him back) enough to officially set (or miss) a world record.

High altitudes can also boost a runner's performance. With less air at higher elevations, it takes less wind to push a runner forward, said Mureika, a graduate student at the University of Toronto, Ontario.

Wind and altitude together can make conditions unfair when it comes to comparing record times, he said.

In the 1968 Olympics in Mexico City, for example, runners shattered world records. Men tied or broke world records in every race between 100 and 800 meters long, in both the 4-by-100- and 4-by-400-meter relays, and in many of the hurdles, jumps and throws. Women set world records in the 100 and 200, 4-by-100-meter relay, long jump and shot put. Olympic records were set or tied in all the other women's running events and many of the men's.

But Mexico City sits nearly a mile and a half above sea level, Mureika pointed out, so its air is only 76 percent as dense as air at sea level. Runners in the 100-meter dash - a race too short for the altitude to tax the lungs - sliced easily through the thin air, making sprint times faster than they would have been at sea level. A 10.00 at sea level would be the same as a 9.93 in Mexico City, Mureika calculated.

Mureika wasn't the first to realize that wind and altitude affect a runner's speed. In the 1930s, runners were looking for ways to better cut through wind and reduce "drag." During the past decade, attempts to use mathematical models have assumed that a sprinter's speed stayed constant throughout the race.

In reality, Mureika said, a runner's speed is faster in the first half of the race than at the end. The initial explosion out of the starting blocks drives the runner forward early on.

Mureika used a simple version of his model to create a calculator that would adjust race times. It spits out numbers that seem to challenge history.

For example, Maurice Greene won the men's 100-meter dash at this year's U.S. Olympic trials in Sacramento with a time of 10.01 seconds. That's slow for Greene and far from his world record of 9.79. But, Mureika said, sprinters had to push through a strong head wind that day, blowing toward them at 1.7 meters per second. He used his model to calculate that Greene could have finished the race in 9.91 seconds at sea level and without the wind.

"It shows that these great times can be masked by these head winds," Mureika said.

Mureika has also recalibrated Greene's world record, set last year in Athens, to 9.80. The women's record of 10.49, run by the late Florence Griffith-Joyner at the U.S. Olympic trials in Indianapolis in 1988, is already controversial because of gusty winds that day and a potentially faulty wind gauge.

Mureika said his recalibrations set her time at 10.72. That would make some of Griffith-Joyner's other performances better than her official record run but still leaves her the fastest woman in history, Mureika said.

His calculations also show, though, that some previous records might have fallen in slower-seeming races. "It shuffles around the record books a bit," he said.

Though the corrected 100-meter-dash times seem pretty accurate, as far as biomechanist Jesus Dapena can tell, he doesn't expect the International Amateur Athletic Federation, track and field's governing authority, to use Mureika's calculator to rank athletes or rewrite record books anytime soon. "I would not recommend it at this point," Dapena said. "We don't know how accurate it is."

Mureika's numbers aren't that different from the results of some previous models, said Dapena, of Indiana University in Bloomington. But, he said, incorporating the runner's change in speed throughout the race may bring Mureika closer to his goal of modeling longer races, such as the 200- and 400-meter races.

Modeling longer events is more complicated. Running around a curve throws a mixture of wind conditions into the equation. Fatigue also makes a runner slow down more by the end. Muscles need more oxygen in longer races, too, making the altitude adjustment more complex.

For now, the calculator might help sportscasters glamorize slow races - at this year's Olympics in Sydney, Australia, for instance.

Many worry that running times will be mediocre in Sydney, Mureika said. The positioning of the stadium may create swirling winds that could slow runners down.

Mureika has considered taking his calculator to NBC, which is televising the Summer Olympics. "Just plug in three numbers and - boom, out pops this record time," he said. The calculations might help inspire disappointed fans. "After the race, you can say, `Well, that was an incredible race. It just didn't look like it.' "