The development boom in Fairfax County may have clogged highways, strained some public services and endangered open space in the county. Now some residents are grousing that Fairfax's new industries are creating an equally troublesome problem: a glut of athletes.

A number of residents complain that sports fields long used by established athletic leagues and by residents' children are being overrun by the employes of some of the new companies moving into Northern Virginia.

"I've heard reports of business teams going in and booting the younger kids off the fields," said Craig Palmer, a member of the Fairfax County Athletic Council.

The council, reacting to complaints from Reston where much of the county's business boom has occurred, is recommending that county planners require developers and businesses to supply "athletic impact statements" before the council approves any further projects.

The proposed statements would be similar to the environmental impact statements that must accompany new construction in the county, but the sports pronouncements would estimate the new development's effect on nearby athletic fields. The issue is particularly pressing in western Fairfax, where Reston residents recently found their softball fields flooded with teams fielded by new companies.

The fields there are maintained through fees paid by the community's residents, and homeowners are demanding that the facilities be reserved for their use and their children's.

"We can't allow [the companies] to use our fields on a regular basis right now," said Susan Grim, secretary of the Reston Homeowners Association. She said a quick solution is essential in the Reston area because: "There's going to be less and less space for recreation facilities, as more and more companies move in."

One of the companies involved in the dispute is Advanced Technology Inc., a professional services firm with 500 employes that moved into Fairfax in late 1984. Because of the opposition of Reston residents, the company's newly formed seven-team intramural softball league has no place to play.

Donna Rogers, who coordinates the company's recreational program, said in an interview this week that the company is weighing at least three options: paying the Reston Homeowners Association for use of its fields, supplying equipment in exchange for the right to play, or helping to maintain the fields in order to win playing rights.

Rogers said she is sympathetic to the residents' concern, but that they should consider the positive impact the new firms are having on Fairfax.

S. Larry Fones, recreation director in Fairfax County, said this is the first time the county has encountered this problem. He said the 814 county-owned playing fields were adequate to meet the demands of the more than 131,000 persons who used them last year.

"We've been able to handle the existing organizations through the years," Fones said. "But if the business sports programs will be as large as they're saying they will be, there won't be enough space to accommodate everyone."

Fones said the county probably will not be able to determine how serious the shortage will be until January, which is the cutoff date for teams to apply to use the playing fields.