It took 22-year-old Sebastian Coe just 41 days this summer to capture the heart of the British sporting public and the world's attention by becoming the first runner ever to hold world records for the 800 meters, the 1,500 meters and mile simultaneously.

He began on July 5 by running 800 meters in a record-breaking 1:42.33 at Oslo's Bislet Stadium. Coe returned to Oslo less than two weeks later to run the fastest mile ever in 3:48.95 against a top field on July 17. If Roger Bannister, who first broke the four-minute barrier in 1954 had run his best mile in that race, Coe would have beaten him by a good 75 yards.

Coe concluded his tour de force by setting a 1,500-meter record of 3:32.03 in Zurich Aug. 15. Running a distance he had seldom raced before, Coe ran away from the field and rewarded the wildly cheeering crowd with two victory laps that emphasized the effortlessness of his feat.

Who is Sebastian Cole?

He is an economics student from Sheffield, England, who loves jazz and was not even considered Britain's best miler before this summer. At 13 he was offered a chance to join a professional soccer training scheme, which he turned down because he didn't think he could become a top-class player. At 14 he won the Yorkshire Schools cross-country championship. Running seemed to fit and, as they say, he hasn't looked back since.

But no one had Coe pegged to become the world's greatest middle distance runner. No one except, perhaps, his father, Peter Coe, an engineer who also is Sebastian's coach.

Over the years, he and Sebastian have developed, according to all accounts, a remarkable father-son coach-athlete relationship. They devised a training schedule that had Sebastian running only 53 miles a week from last October up to April, considerably less than the 100-plus miles of roadwork that many top runners have forced themselves to endure for the last decade to achieve world-class success.

Until his first win in July, Coe not only ran only 53 miles a week, he also spent most of May studying for college exams -- so demanding that he says he was only able to work out twice in two weeks. Completing his exams in early June, Coe promptly fell ill with flu for a week. Twenty days later he began his record-breaking string of races.

No one, not Sebastian, nor his father, nor the British press have been able to understand how he could suddenly run so fast. As Bill Trevor, a BBC sports reporter put it, "Forty-two days ago no one thought Seb had it in him to become a world-record holder. He didn't even expect to win the mile -- he'd only run three mile races in his whole life. But like he said before the 1500 win at Zurich, 'if it comes, it comes.'"

In some ways the 1500-meter win last week in Zurich was the most remarkable of Coe's remarkable races. He had run only five four-lap races in his career, and the 1500 was new to him.

He had difficulty pacing his laps, running a speedy 54.2 first lap only to follow with a 59-second second lap. Coe wound up alone in front for the last 800 meters of the race, with little idea of how to pace himself.

In the end he beat the old record by just one-tenth of a second. That was enough to assure him of his place in track history and bring the Swiss crowd screaming to its feet. If Coe had been running against someone who could have paced him, he might well have knocked a second off the old time.

After his 1500-meter triumph, Coe told the press that he was "just a boy at this distance." While that is true enough, it is precisely the kind of honesty and humility that has made him a hero in British eyes.

As a 22-year-old boy wonder, Coe is exactly the kind of fresh hope a too-long depressed British public needs. He epitomizes the British ideal of good manners and sportsmanship. With race promoters and journalists crawling over each other for Coe's attention, he has still steadfastly refused to let it go to his head.

Two weeks ago, after winning the 800 meters in Turin, Italy, Coe stayed up until 10 P.M. answering questions and giving interviews to journalists from all over the globe, while his fellow competitors had long since headed for waiting hotels, bars and restaurants.

After winning in Oslo, Coe walked into a standing ovation from his just-defeated rivals, who were waiting at a restaurant. His reaction was typical when asked about it afterwards, "I was very embarrassed."

Embarrassed or not, Coe is now the world's fastest man between 800 and 1500 meters. With the 1980 Olympics looming, every top middle-distance runner in the world is looking at Coe's style and times as the standards they must meet.

Can someone who is "just a boy" at world-class running stand up to the pressure? That question is occupying many British running enthusiasts who fear that Coe may have "run himself out" rather than carefully building up to an Olympic peak. But Coe claims not to be affected by pre-Olympic gloom merchants. He says he would rather thave his three world records than Gold in Moscow.

If Olympic jitters weren't enough of a distraction, Coe faces another problem closer to home: Steve Ovett -- the former European 1500-meter champion, British mile champion and, before this summer, the top British hope for the 1500 in Moscow.

Coe has raced in out of the blue to pull the track out from under Ovett's feet, and the word is thatOvett doesn't like it. He is an aloof and prickly athlete who had rightly assumed he was Britain's undisputed middle-distance Olympic hope. That no longer is so after Coe's recent footwork.

In style, the two British runners couldn't be more different. Ovett is a 24-hour-a-day running professional, seasoned in world-class athletics, a veteran of misunderstandings with sports journalists, race organizers and British athletic officials. After one such disagreement, Ovett refused to run in the Oslo mile race in which Coe set his record.

Last week, Ovett withdrew from the Zurich meet when the organizers refused to let him run the 800 meters,. This time Coe set a record at Ovett's "own" 1,500-meter distance.

While there is no doubt that both Coe and Ovett will run for Britain in Moscow, it is not yet clear whether Ovett will have the 1500 meters to himself as he once thought. Coe's times were good enough to beat Ovett's best by 10 yards in the mile and the 1500 meters.

Meanwhile, the British press is busy comparing the two of them, usually favoring Coe over Ovett's seemingly distant assuredness. The two top British runners have not met in a race this year and are not likely to. But Ovett has fanned the flames between them, reportedly saying after he was turned down by the Zurich race officials, "Whoever wins this race will know it's a hollow victory because I'm not there."

Coe has not yet said whether he regards his victory as hollow and isn't likely to. He claims to want only a needed vacation, which he is now enjoying. Still an amateur, Coe will live for next year on sporting fellowships provided to allow him time for Olympic training. It will be the first full-time running year of his life.

As for the remaining months of this already bountiful year, Coe probably will run in two more major races, at 800 meters in Brussels and perhaps a specially scheduled 1,000-meter event on Aug. 31 in Britain. Everyone is speaking very softly about the 1,000 meter run -- and Coe has cautioned the press "not to expect a world record."

But the line dividing hope from expectation is very thin, and there is no doubt that a great many people here are hoping very hard for Coe to become the first man ever to hold four world middle-distance records. $13-"Picture, Sebastian Coe