John F. Herrity, chairman of the Fairfax County Board of Supervisors, who has made rebounding from heart attacks a part of his style, is back following his latest attack -- and running.

Herrity declared in an interview yesterday his intention to run a 10-kilometer race this spring and said that "there ain't no way" he would curtail his workload.

"I have no intention of doing anything but going back and going 100 percent," he declared in his first interview since he suffered a heart attack Jan. 10 -- his third in nine years. "You either do 100 percent, or you quit."

He said he still is considering running for the 8th District congressional seat now held by Rep. Stan Parris. Parris is seeking the GOP gubernatorial nomination in Virginia.

Herrity, a Republican serving his third term on the Board of Supervisors, has missed four of its meetings since the heart attack. He said he plans to return for the board's next meeting, scheduled for Feb. 25.

Slouched against his desk with his arms folded over his chest, Herrity appeared fit -- he is down to 180 from 190 pounds -- and struck a low-key but determined tone in the hour-long talk at his insurance company office. Afterward, he headed for George Mason University's field house, where he said he planned to jog a couple of miles.

Herrity acknowledged that he has trouble sleeping and is taking medication for high blood pressure and an irregular heart beat. He also said his family and friends had expressed concerns about his workload.

He said he has stopped smoking cigarettes "cold turkey" and has adopted a "Herrity diet" that is low in salt and fat.

He attributed his quick recovery to his good physical condition before the heart attack. He was jogging four miles a day, but also smoking 10 to 15 cigarettes daily, he said.

Asked about suggestions that he adjust his work schedule to ease the tensions brought on by politics, Herrity turned almost combative.

"If you go, you go with your boots on," he said. "I'm gonna go doing the things that I want to do, the things that I think make sense, the things that I want to accomplish.

"That's one of the reasons why I try to keep in good physical shape -- so it enables me to do the things I want to do."

Herrity suffered the heart attack about 10 p.m. Jan. 10 in his insurance office, just hours after a meeting with D.C. Mayor Marion Barry to discuss the city's Lorton Reformatory. He said he felt a "deadening" pain in his left arm and drove himself to a nearby hospital.

He said the pain was mild compared with the successive heart attacks he suffered in 1976. "The worst thing about a heart attack is the psychological impact," he said.

Herrity dismissed questions about Barry, who remarked at a Jan. 16 press conference: "I guess our meeting affected him somehow."

Barry's remark drew the anger of county supervisors, but Herrity called publicity about the incident a "media event." He said Barry had apologized with a phone call and a letter.

Herrity said he has received hundreds of cards and letters since the heart attack, as well as donations to the American Heart Association on his behalf.

"It's been heartwarming," he said.