The first two Olympic medals of the 1996 Summer Games went not to competitors in one of the athletic events, but to an amateur runner and an avid swimmer who devoted their careers to showing the lifetime health benefits of vigorous exercise.

Ralph S. Paffenbarger Jr., a research epidemiologist and physician at Berkeley and an affiliate of both Stanford and Harvard, was awarded an Olympic medal July 14 along with British scientist/physician Jeremy N. Morris for independent research showing the link between physical activity and lowered risk of coronary heart disease.

The medals accompany the first $250,000 Olympic Prize in sport science, inaugurated this year by the International Olympic Committee and endowed by Parke-Davis pharmaceuticals. The prize was awarded at the opening ceremony of the 105th session of the International Olympic Committee in Atlanta.

Paffenbarger, a fit 74, is known for his pioneering studies of Harvard graduates and San Francisco longshoremen. These studies showed that exercise lowers the risk of heart disease and reduces risk of many other diseases. He showed that the more you exercise, the less chance you have of dying of a heart attack, and that men who exercised vigorously and burned at least 2,000 calories a weekãroughly the equivalent of running 20 miles a weekãhad the lowest risk of all.

These findings became the foundation for the American College of Sports Medicine's fitness recommendations and are the subject of a new book by Paffenbarger and Eric Olsen called "LifeFit: An Effective Exercise Program for Optimal Health and a Longer Life."

"We know that being physically active and physically fit is a way of protecting yourself against coronary heart disease, hypertension and stroke, plus adult-onset diabetes, obesity, osteoporosis, probably colon cancer and maybe other cancers, and probably clinical depression," Paffenbarger says. "Exercise has an enormous impact on the quality of life."

Paffenbarger himself was an avid runner and marathoner until a few years ago, when he was forced to quit because of knee problems. From 1967, when he first took up running at the age of 45, until 1993, he ran in 151 marathons and long distance races.

He continues his exercise regimen today with daily 3- to 4-mile walks. His running and professional exploits are detailed in a glowing tribute on the World Wide Web, at http://www2.pitt.edu/~pahnet/paff/paff.html.