Diana Nyad is escorted by kayakers as she swims towards the completion of her 111-mile trek from Cuba to the Florida Keys. (REUTERS/Andy Newman/Florida Keys News Bureau)

When 64-year-old Diana Nyad stepped onto the beach in Key West on Monday, she became the first person to swim the 110 miles from Cuba to Florida without a shark cage. She also joined a very exclusive, enviable club: Athletes who achieve amazing physical feats long after the retirement age for their sports.

Fauja Singh, nicknamed the “Turbaned Tornado” by his fans, began running marathons at age 89 and completed nine before retiring in February at age 101.

Fifty-four-year-old Jeannie Longo, the “grandmother of cycling,” finished fourth in the 2008 Olympics road time trial — far ahead of several cyclists who weren’t even born when she competed in her first Olympics in 1984.

Team sports have their own aging stars, as well: Yankees pitcher Mariano Rivera will turn 44 on Nov. 29, golfer Jack Nicklaus won his last major tournament at the age of 46, and hall-of-famer George Blanda didn’t retire from football until he was a month shy of his 49th birthday. Martina Navratilova, who won her 59th Grand Slam with a doubles title only two months before turning 50, serves as a “fitness ambassador” for AARP.

Amazingly, these mature athletes are no longer the outliers they used to be. According to data parsed by the Boston Globe, more older athletes compete in basketball, hockey, football and baseball than 30 years ago. In 1982, there were four players older than 35 in the NHL, and 14 in the NFL. Now there are 56 and 40, respectively.

What’s their secret? It’s actually not all that secretive, statistics and sports medicine suggest. Extreme athletes like 101-year-old Singh and 96-year-old Artin Elmayan, the world’s oldest ranked tennis player, probably benefit from good genes. But aside from that, good nutrition and training go pretty far: Orthopedic surgeon and sports researcher Vonda Wright told the Washington Post in 2011 that “how we age is 30 percent genetics and 70 percent under our direct control.”

Nyad’s a perfect example in that respect: Her training and nutritional regimens are both grueling and carefully calculated. Leading up to her third open-swim attempt in 2011, she did 100 burpees a day and biked 100 miles every Friday, in addition to her time in the pool. Nyad’s diet, which averages 9,000 calories on training days, includes regular protein shakes and a complex energy drink made with water, electrolytes and predigested proteins.

Clearly, something’s working.

Nyad has told interviewers that she feels stronger now than when she was 25, and when she finished her swim Monday, she had a few words of advice for her fans: “You’re never too old to chase a dream.”


Nyad says achievement wasn’t athletic

Nyad completes Cuba-to-Florida swim on fifth try

Nyad nearing Florida, swimming well

Nyad “looking good”

Nyad’s 2012 attempt fails

Nyad abandons 2011 attempt