But Mackela, a retired government attorney, eventually found a coach and started competing.
Some things have changed since college. "Most of us are a little heavier, so in somersaulting dives, if you haven't done it in 30 years, you have to find out where you are," she said.
Older adults also need to stretch more — and conquer fears that a younger person might not have. "You understand more as an adult what can happen if you do something wrong," she said.
Bernhard Stamm, 74, of Ashburn, Va., learned that lesson three years ago, when he resumed doing field events after a hiatus of more than half a century and got so enthusiastic that he pulled his hamstring after failing to warm up properly.
"You've got to listen to your body," said Stamm, a retired architect who was a track and field athlete in high school in Switzerland. He now has 25 gold medals in senior competitions under his belt.
Stamm recently competed in the Northern Virginia Senior Olympics in the standing long jump, running long jump, high jump, javelin, shot put and softball throw. He'll even be adding some tricks he didn't know in high school.
"The Fosbury flop, where you jump over backwards," he said, referring to a move popularized in the 1968 Summer Olympics. "That didn't exist when I was a kid, so two years ago I learned it, and now I'm doing a Fosbury flop."
Nyad is a baby boomer, part of the generation born between 1946 and 1964, and her feat may foreshadow a change in attitudes among a generation that has never liked to think of itself as old.
"She just didn't give up, she was determined to do it," Cooke said. "I'm thinking, 'All right, I can't let these little aches and pains hold me back; there's things to do, and I'm going to get out there and do them."