As George Allen introduced the speakers for a seminar on medical implications of sports activities for senior citizens yesterday at the Shoreham Hotel, he described his expertise in the area.

"As the coach of the 'Over the Hill Gang,' " he said, "I know that conditioning is most important."

For the next 90 minutes, three experts in the area of medicine and sports -- Dr. James Nicholas, Dr. Samuel Fox III and Dr. Barbara Drinkwater -- testified on the virtues and problems involved in exercise by the elderly.

Fox, professor of medicine and director of the preventive cardiology program at Georgetown University, spoke about heart and circulatory problems, pointing out that "over half the deaths of all Americans are attributable to coronary artery disease and other cardiovascular disease.

"I'm here to stimulate all to get off their fatty acids and do something," said Fox. "Studies on more activity indicate a decrease in cardiovascular incidents." He recommended a regimen of 15 minutes of continuous dynamic activity (running or brisk walking) three to five days a week.

Dr. Nicholas, a former team physician for the New York Jets, recommended an aerobic fitness program that gets the entire body involved, such as swimming, running or walking.

Dr. Drinkwater, a research physiologist at the University of California-Santa Barbara, said that women who remain active as they get older gain the same physical and psychological benefits as men, such as improvement in cardiovascular fitness, increased strength and flexibility and decrease in body fat.

Participants in this National Conference on Fitness and Aging also had available to them a number of special exhibits featuring all types of excercise equipment, including a computerized stress test machine.

There also were entry blanks for the Post Cereal Fun and Fitness Golden Age Games. The competition in mid-November will include archery, swimming, horseshoes and, of course, shuffleboard. It will be held -- where else? -- in Florida, the retirement capital of the world.

And the ITT Continental Baking Co., was offering a video show on nutrition for older Americans. They also have a number of brochures on the subject available to companies. "We printed them in large type," said Robert Keane, who was manning the exhibit. "And the good part about these leaflets is they are the same size as an envelope, so you can stuff them in with the pension checks."