DONALD BURGY runs five miles each morning, matches that distance in a swimming pool later in the day and sneaks in a few rugged sets of tennis between graduate classes in psychology at Catholic University.

Burgy, 22, is in training.

For the Boston Marathon? A new version of the decathlon? A Wimbledon hopeful maybe? No, Burgy is preparing for the 1980 Olympics in the international skeet shooting competition.

"Competition begins at 9 in the morning and can last as late as 6 at night so you have to be in top shape," said Burgy, winner of three straight national collegiate skeet titles. "You've got to be able to compensate for nervousness, and a 10-pound gun can get pretty heavy after awhile."

Burgy said running also helps his ability to control his breathing - an absolute necessity for an event that, in top-level matches, demands at least 95 per cent shooting accuracy. Burgy swims to build strength and muscle tone. Unlike weightlifting, which might add unwanted bulk, working out in the water keeps Burgy agile enough to hit four-inch circular targets moving nearly twice as fast as the highway speed limit.

Tennis helps him maintain eye-hand coordination to sight those speeding targets with pinpoint accuracy.

And, of course, Burgy shoots - once a week at the National Capital Gun Club in Gaithersburg.

"I actually think that less practice over a long period of time is better than a lot of concentrated practice," he said. "You always run the risk of reaching a peak and then running into a slump if you shoot too much. A little bit at a time - once or twice a week, shooting one or two rounds - allows you to remember your mistakes and correct any bad habits you might be forming."

Burgy began shooting eight years ago after asking his father for a B-B gun. Donald Burgy Sr., a former Army marksman, decided it would be better for his son to learn to shoot a real gun in a saft and proper atmosphere, so the two joined the Izaak Walton League, which sponsors shooting classes.

Burgy first learned the American version of skeet, appropriately named American Skeet.After three years he wanted more challenge, so at age 17 he switched to International Skeet.

Differences between the styles are significant. In international, the target may be released at any time in a three-second span. In American, the release is immediate.

International rules require that the shooter's gun be held at hip level, with the butt of the gun visible below the elbow until the target is released. American rules allow the gun to be held at shoulder level from the start.

And the target in international moves 90-110 miles per hour, while in American it's only about to 60.

Otherwise the proceedings are similar. The shooter fires from each of eight stations arranged in a semi-circular pattern between two "houses" 44 yards apart.

When the shooter calls "pull," a 4 1/2-inch clay disc is flung electronically from the "high house" (about 10 feet up). After a shot, this process is repeated for the low house (about three feet). At certain stations, the shooter loads his gun with two shots and attempts to hit two targets which zip simultaneously through the air at different angles. After four 25-shot rounds, the shooter with the highest number of "hits" is the winner.

"It sounds like a cliche," said Burgy, "but the most important thing when you shoot is to concentrate on each specific target. You can't start thinking about the shots you missed or the ones the guy in front of you missed or you'll get in trouble. In order to psych up for a match, you really have to psych down."

Burgy would like to see more people try international skeet, and is enthusiastic about skeet in general. In 1974, as a sophomore at Swarthmore College, he founded a skeet club. By the end of his senior year, Burgy had taught 50 students how to shoot.

"Teaching was a very valuable experience for me," he said. "It really helped my own shooting. When you teach, you have to analyze each person's mistakes in order to correct them. The entire process kept me very conscious of my own shooting style. The year I made the team was after I had taught fairly consistently each week."

The team Burgy made was the U.S. International Shooting Team. In May, 1975, he became the youngest person ever to qualify for it. Burgy finished fourth in the competition at Chardon, Ohio, shooting 289 out of 300 targets. That made him eligible to compete in the Pan-American Games in Mexico later in the year - the last step before the Montreal Olympics.

As a warm-up to the Pan-American Games, Burgy participated in the Mini-Olympics held in Montreal in July, 1975.

"I wanted to try out the facilities," he said. "This was technically my first international competition so there was some pressure even though I knew that I was still going to the Pan-Am Games."

At the Pan-American Games it quickly became clear that the American contingent was not supposed to feel as if Mexico was its home away from home. Marching into the stadium for the opening ceremonies, the team received a unanimous round of jeers and hoots.

The hazing carried through into the competition. "The Cuban coach had watched us during practice," Burgy said. "On the first day of competition, right after I shot from the station with the most difficult angle, he came up to the referee and complained that my gun was in the wrong starting position. First of all, it's technically illegal for a coach to confer with the judges during a round, but still they made me reshoot the shot. I had been warned that this would be one of the major tactics and that was right. It happened to a lot of shooters during the competition."

Burgy shot well, but by the end of the second day he knew that he was out of the competition. When the event ended, Burgy was 20th with a score of 189 out of 200. Athos Pisoni of Brazil had won with a near-perfect score of 199. Two Americans also placed above Burgy. Robert Schulele took second with 196 and John Satterwaite captured seventh with 192.

"I wasn't really upset because I've been brought up with the attitude that everybody can't always be a winner. And really, I have another 30-40 years at this sport. In any case, it was an invaluable experience. I learned a great deal from the other athletes about training and shooting techniques. Maybe the most important thing I learned is to ignore all the harassment tactics. It's just part of the sport at this level of competition and if you let it get to you you're in trouble."

But believe it or not, shooting is not Burgy's top priority.

"I'm definitely pushing toward the Olympics. I shoot because I enjoy it and fortunately I can shoot well. But I won't devote all my time to it. I really made that decision when I chose college over the U.S. Army Marksmanship Division. I'm getting married in July and I still have to graduate from Catholic University. Shooting is second place . . .not too far behind, though."