Parry O'Brien, who revolutionized the sport of shot-putting with his spinning technique and went on to break 17 world records and win three Olympic medals, has died. He was 75.

O'Brien died Saturday of a heart attack as he competed in the 500-yard freestyle at a swim match, said his wife Terry. He became an avid swimmer after shot-putting became too hard on his joints, she said.

"He was at lap 11, getting ready to switch and he stayed at the wall," she said. "That's when I realized something was wrong."

Born in January 1932 in Santa Monica, O'Brien turned to shot-putting as a freshman in high school after an injury in a scrimmage ended his football career.

O'Brien began experimenting with new shot-put techniques in 1951 while attending the University of Southern California. At the time, shot-putters would stand at the rear of the seven-foot-ring, hop, turn 90 degrees and propel the 16-pound iron ball. In the middle of the night after a loss in the Fresno Relays, O'Brien tried out a 180-degree turn.

The idea, he later said, was that "the longer you are pushing, the farther the shot will go." The move became known as the "O'Brien Glide."

The experimentation immediately paid off. Before 1951, O'Brien could not put the shot more than 55 feet. From 1953 to 1966, he broke the world record 17 times, starting with 59 feet, 3/4 inches and raising it to 63 feet, 3 inches.

He won 17 American titles in the shot-put and one in the discus throw. His longest winning streak was 116 meets. O'Brien even appeared on the front of Time magazine in 1956.

O'Brien won gold medals at the 1952 and 1956 Olympics and a silver medal in 1960. In 1964, he carried the American flag in the opening ceremonies and went on to finish fourth.

He was elected to the United States Track and Field Hall of Fame in 1974 and the United States Olympic Hall of Fame in 1984.

O'Brien retired from competition in 1966 and went on to work in commercial banking, real estate and civil engineering. He made his home in Moreno Valley, west of Palm Springs.

He is survived by his wife, two daughters, two stepsons and seven grandchildren. There will be no services per O'Brien's request.