Does Racing in Packs Offer an Unfair Advantage?

John Roach
for National Geographic News
October 1, 2001
In cycling, triathlons, and other races, the leader of the pack may not be out ahead in terms of innate talent.

The "bunching" that often occurs in such events gives some racers an advantage that masks their individual ability. As a result, the person who crosses the finish line first isn't necessarily the most physically and mentally fit competitor in the race.

Many bicycle racers travel in packs so they can share the effects of wind resistance and pick up speed. The race may be won or lost on the final sprint.

And in orienteering, in which participants use maps and compasses to navigate from point to point, runners who see someone up ahead may push to catch up without the help of the map.

Graeme Ackland, a physicist at the University of Edinburgh in Scotland, noticed this pack behavior in orienteering events in Scotland and in cycling and triathlon events during the 2000 Olympic Games in Sydney, Australia. What causes it, he wondered, and could the effect be minimized?

"I noticed the packs forming and started wondering if there was any scientific way to describe it," he said.

Ackland and his colleague David Butler have developed a computer model to show how packs form. They say the model, described in the September 13 issue of Nature, might help race organizers figure out how to stagger the start of an event to avoid pack formation and increase the chances that the most skilled competitor wins.

The model is based on race conditions such as the number of competitors, the length of the course, the time intervals between the competitors' start, and individual speed.

But the most significant factor in determining whether packs are formed, the study showed, was the racers' ability to catch up with contenders up ahead—a variable the researchers describe as the "boost factor."

In cycling, Ackland said, the boost factor is "the knowledge that if you can catch up, you will get a real aerodynamic boost. Pack formation benefits everyone and they [competitors] know it."

"When racing alone, it is easy for concentration to waver and [for a competitor] to slow without realizing it," he added. "In a pack, the other competitors maintaining their speed should prevent this."

According to the computer model, if more than 13 percent of the competitors can see and catch up with the competitor ahead of them, all the competitors will rapidly cluster in pack formation.

Group Advantage

Pack formation in cycling and orienteering races gives competitors the edge of working with one another to reach the finish line in the fastest time.

In cycling races, when an individual competitor sees a rider out in front, he or she tends to chase the rider to take advantage of the aerodynamic effect of "drafting." The two riders then share this drafting benefit, allowing them to save energy, move faster, and catch up to riders ahead of them.

This process continues until the end of the race, when one big group usually crosses the finish line, followed by a gap and then another big group, said Ackland.

"As for people of lesser ability winning because of packs, the obvious example would be sprinters winning stages of the Tour de France," he said. "There's no way they are the best at cycling 200 kilometers (124 miles)."

In orienteering, the race is based on the competitors' skill in using a detailed map and compass to navigate a series of checkpoints in a given landscape.

Sometimes, however, contenders who see another racer up ahead abandon orienteering skills and just run to catch up, said Robin Shannonhouse, executive director of the United States Orienteering Federation.

Although such behavior is frowned on and even considered cheating in certain orienteering events, it is common among younger racers, said Shannonhouse. "They see someone else running by who looks like they know what they are doing and not even consciously they say, I guess, "[The right direction] is the way he is going,'" she said.

Shannonhouse said such behavior seldom pays. "I've been in orienteering since the mid '70s," she said, "and have never seen an instance where cheating actually won something."

Preventing Packs

The findings of the study suggest that race organizers, if they knew certain information about the competitors and the course, could stagger the start of a competition to avoid pack formation, said Auckland.

"If the format has the competitors starting at x-minute intervals, our results enable us to determine how far into the race pack formation will begin to become crucial, and hence to increase x so that pack formation doesn't start until after the race has finished," said Ackland.

In some cases, though, even a well-planned staggered start won't prevent racers from forming packs.

Shannonhouse described a national orienteering competition for high school and middle school students held last year near Atlanta, Georgia. Students from the same school began the race in staggered, six-minute intervals. By the end of the race, entire school teams had finished together, their times precisely staggered by six minutes.

"They all waited and ran together," she said.

"But they didn't win," she added. "The ones who won are the ones who should have won."

© 1996-2008 National Geographic Society. All rights reserved.