They have gathered more than 4,700 strong from across American and 22 foreign countries to test their legs, lungs and life styles on a 26-mile 385-yard run from a sleepy little New England village into the heart of this Massachusetts metropolis.

The occasion is the Boston Marathon, and there will be no slouches in the field for the 82nd running of this Patriots Day affair that begins at noon today. Every man under 40 has finished at least one marathon in less than three hours, and every woman of the 227 entered has been timed under 3:30.

Those clockings are built from the blood sweat and wind-blown tears of hours of [WORD ILLEGIBLE] training, mile after mile, day after day, under sultry summer suns and bone-numbing February freezes.

The payoff for most will come at midafternoon today, when the race is over and the memory of a million pairs of clapping hands along the route from [WORD ILLEGIBLE] , Mass., to the Prudential Building downtown will have made the agony seem worthwhile.

For a select group of world-class runners, finishing will not be enough. While most in the field will be content to better personal records (PRs for aficionados), this marathon also will be highly competitive up front,

There are 21 men entered in the race who have completed marathons in 2 hours 20 minutes or better. And with temperatures expected to be in the low to middle 50s - ideal for this distance - anyone of them could cross the finish line first.

Over at the Eliot Lounge, a local marathoners' mecca a few blocks from the finish, bartender Tommy Leonard spent most of yesterday dishing out spaghetti and beer to carbohydrate-conscious runners and offering predictions to anyone who cared to listen.

"It has to be Billy Rodgers all the way," said Leonard, referring to the local hero and prerace favorite, Bill Rodgers, the 1975 chamiopn and American record holder in 2:09.55. For the long-division fanatics, that's an average of 4:57 a mile.

"The weather is perfect and Billy just keeps getting better and better," Leonard said. "He'll go into overdrive when all those other guys fade out. I'm telling you, the man runs like pure whipped cream."

Most of the prerace puffers has centered on the anticipated duel between Rodgers and Frank Shorter, the 1972 Olympic champion who has entered the Boston Marathon for the first time. He declined to run here in the past because marathon officials refused to pay his (or anyone else's) way.

But shorter is now a thriving manufacturer of running apparel and a fitness consultant to several large corporations. Running Boston, he knows, will be good for business, particularly if he wins.

"I wouldn't bet on me," Shorter said the other day, before going into what he described as "my race-day seclusion act. I haven't run a marathon since October of 1976. I had foot problems, then a hamstring pull, so I've been pretty much out of commission. It was getting frustrating for a while, but I'm starting to feel healthy again.

"If I get through it, I'll be happy. If I start limping or hurting, I'll stop. I'd be pleased to average about 5:10 a mile, but I'm not thinking about Rodgers or anybody else. I like the guy. He works hard, he trains hard, and he's a great competitor. I'd just like to do well and, if I can win, that would be nice, too."

Rodgers also was playing the psychout game when he insisted earlier in the week that he is really not in his best shape, even if he has won seven of 10 races he entered this year at distances from 10,000 meters to 13 miles. Two weeks ago, in his last competition, Rodgers was an easy winner in Washington's Cherry Blossom Classic over 10 miles.

Rodgers dropped out last year in Boston at the 18-mile mark on a brutally hot day. But the heat should not be a factor today and that is very much in his favor. "If he puts on his white gloves," said Leonard, "look out."

Defending champion Jerome Drayton should be among the leaders, if he decides to show up. Drayton, a cantankerous Canadian, complained bitterly about being jostled and almost trampled at the start last year, and was equally unhappy about the dirth of water stops along the route. In his postrace press conference that day he vowed not to return unless changes were made.

Drayton relented and entered the race this year, but pulled a hamstring in training last week.

"We don't know if he's coming or not," said Jock Semple, the crusty old Scotsman who has organized this race for years. "Ta tell ya tha truth, he can drrrrrrop dead as far as I'm concerned."

Other leading contenders include Randy Thomas, who trains with Rodgers and has 2:13.28; Don Kardong, a member of the 1976 Olympic team, and Jeff Wells, a seminary student from Dallas who won the Honolulu marathon and has a 2:13.15 best clocking.