They are trying to run the Boston Marathon into the ground. Last week, and through Monday when more than 6,000 runners dashed, loped and hobbled the 26.2 miles from the village green in Hopkinton to downtown Boston, the talk was money and commerce.

It appears that this was to be the last year that the Boston Marathon --America's oldest, largest and most tradition-hallowed mass-participation sporting event--could brighten the athletic scene as a model of pure amateurism.

Next year, according to officials of the Boston Athletic Association, prize money may await the speediest finishers. Race day may be shifted from Patriot's Day to Sunday, the better to accommodate television, which can use the event to hawk still more light beer and all-new radial tires. Top runners are to be paid expenses, a previously unthinkable pampering.

Time magazine's Tom Callahan, who could do a sub-three-hour marathon if he ran as well as he writes, is accurate in saying, "The Boston marathon is about to turn pro."

The thought makes me weak in the knees. I've run Boston three times. To be there--well to the rear of the pack, I admit--was an incomparable thrill. We were amateurs all, from 50 states and 25 nations. We were running for the pure joy of it. World-class runners covered the same roads at the same time with plodders like me who aren't even neighborhood-class. While breathing deep as we crested Heartbreak Hill at the 20-mile mark we were inhaling also the amateur traditions that seemed sure always to be guarded from the profiteers who have profaned the rest of the sports world. All of us at Boston paid our own way to get there, a payment that included--if I may get carried away--the meeting of some strict time qualifications. All of us were given the same prize at the finish line: a bowl of stew. No T-shirts, no patches. Only stew. The other prize was to enjoy the immersion--a plunging, really--into the glories of such heroes of the past as Clarence H. DeMar, who won seven Bostons, and Ellison Brown, who won two. They ran as we ran: unpaid, unbought and untelevised. The bucks stopped at Boston.

I know that thoroughbred runners look on my kind as dilettantes who want to preserve the amateur code at their expense. Not true. I've been arguing for some time that Bill Rodgers, Grete Waitz, Frank Shorter and the other fleet-foots deserve to cash in on their talents. If everyone else is milking the market--from shoe companies selling air-bubble soles to psychiatrists pushing running therapy--the runners ought to be profiting too.

But not at Boston. Let this be the one holy temple of sport where the money-changers are kept out. It's been that way for 86 years. Let the upstart New York Marathon be a 26-mile river of money, if the top runners want that kind of swimming.

American sports are so controlled by commercialists that an appearance of amateurism is routinely devised to create a clean image. At the Masters golf tournament, the WASP-y snobs who host the event pretend that the professionals are competing only for The Green Jacket. The Green Dollar is not mentioned. The media go along with it, not daring to suggest profanely that if indeed only a green jacket were the prize not a pro would show up.

Should Boston be commercialized and professionalized, who knows how low it might sink. Perhaps George Steinbrenner, tired of his losing Yankees, will sign Bill Rodgers to a contract. But what if Rodgers is beaten? The headlines would read: "Steinbrenner Berates Rodgers for Laziness on Heartbreak Hill." And perhaps the next running film to replace "Chariots of Fire"--a celebration of amateurism--will be "Chariots of Money."

Aside from having been privileged to taste the delights of the Boston Marathon, I have another reason for caring about the event's purity. Four years ago, on the day after the race, I interviewed Will Cloney, the revered and longtime director of the event. This is "a great, great amateur spectacle," he said, "because you know that the people out there are running for the sake of running. They're not running to get a promotion in their job or to make money. They're just doing it as a personal test, and that's wonderful. That's the whole spirit of the Boston Marathon."

I believed it. It made the running easy. For 26 miles at Boston, such a thought was the wind at everyone's back.