Glenn Preston's exercise regimen is typically no more taxing than typing, walking to the office water cooler and pushing a computer mouse across his desk at a Chantilly high-tech firm.

"The most lifting I do is . . . lifting a doughnut to my mouth," said Preston, 38.

But yesterday, the communications engineer and 19 of his colleagues had a real workout. They pulled "Daisy," a 145,000-pound, 727 aircraft across 12 feet of tarmac at Washington Dulles International Airport in 7.1 seconds.

"We didn't do bad for a couple of old geeks," Preston said.

Preston's was one of 40 teams that each paid $1,000 to see who was fastest at pulling Daisy in what was the highlight of yesterday's seventh annual Dulles Day. The event promoted the region's fastest-growing airport and gave an estimated 10,000 visitors a chance to explore part of its 10,000 acres. It also raised $70,000 for Special Olympics Virginia -- most of it from the plane pull contest.

The plane pull, invented as part of Dulles Day, has raised $300,000 locally in the last six years. It also has become an enormously popular hallmark of Special Olympics fund-raising across the country. For participants, anticipation was almost as thrilling as the event.

"It's a man thing. It's about pride," said Sunny Williamson, 27, an electronics technician for the Navy in Virginia Beach who had driven up for the event. For the last two weeks, he and two teammates heaved his 1989 Camaro around a parking lot to practice. "It sets you out ahead of everybody else."

The winners, from a Navy team, practiced by pulling the Secretary of the Navy's DC-9 across part of an airstrip twice a week. And an all-female team from the Chesapeake sheriff's office pulled a firetruck a few times a week.

Some local police departments had mustered ringers for their teams -- former high school and semi-pro football linemen and competitive body builders -- and they'd buttonholed local sponsors, such as steakhouse chains or gyms, to pay the $1,000 entry fee.

"To do this is big-time bragging rights for the whole year," said Tony Spencer of the Prince William County police department.

During the three-hour contest, teams took turns grabbing a 2 1/2-inch-thick rope attached to Daisy's front wheel assembly. At the call of "Ready, Set, Go," the line of straining, sweating and groaning teammates inched the plane along a 12-foot-long path of tarmac. Yesterday the fastest team did the job in 5.9 seconds. The slowest took nearly 11 seconds.

But plane pulling isn't just about brawn.

"We're using our brains rather than brawn," said Barbara Zeiller, 54, a personnel manager for a Sterling high-tech equipment firm.

"We'll pull hard and not stop until we're done," explained Greg Moore, 29.

After some competitors pulled muscles last year, organizers devised a new category of contestants and gave a prize for the "lightest" team. That trophy went to a McLean-based commercial real estate company team of teenagers, children and their parents. Together they weighed in at 2,770 pounds, about a ton lighter than Preston's team, and pulled Daisy 12 feet in 10.7 seconds.

For those not looking to break a sweat, there were air-conditioned shuttles to the Air and Space Museum's annex at the airport, where a SR-71 Blackbird spy plane from the late 1960s was on display along with antique cars and other planes.

"Ah, oh. That's what I want to see," said Steve Dulkerian, 41, of Crofton, heading to the SR-71. "It's absolutely incredible. You never get to see it up close."

CAPTION: A team from the Dulles Fraternal Order of Police tugs on a Boeing 727 as part of a plane-pulling contest at Dulles International Airport. The event, a fund-raiser for Special Olympics Virginia, was part of the seventh annual Dulles Day.