Every morning, Tony Diamond goes to a local park for an hour of fast walking. Then he runs for another hour. He also goes to a gym two or three times a week for muscle training. The retired navy captain won three medals at the 2015 National Senior Games in the road race and the race walk in his age group, 85 to 89.

“My current age is 86 years old and my fitness age is 44," he says. “I think I have such a good number because I did a lot of exercise during my life. I've been exercising since I was a little boy.”

Helen White, a versatile athlete who won a silver medal in pickleball at the 2013 National Senior Games, plays basketball and also teaches the sport to senior groups.

“I'm 62 years old and my fitness result showed that I was 32 years," she says. “It really wasn’t until I turned to 50 that I decided to become much more serious and focused about play, and just making sure it is daily part of my life.”

White and Diamond are among some 5,000 competitors in the National Senior Games, a biennial competition for athletes over 50 that was recently held in Minnesota, who took part in the study on fitness age.

The research, led by Dr. Pamela Peeke of the University of Maryland in coordination with Dr. Ulrik Wisloff of the Norwegian University of Science and Technology, who developed a fitness calculator, found that older athletes’ fitness age is more than 20 years younger than their chronological age.

“You simply input very straightforward data," said Peeke, explaining how the study was conducted. "We ask you questions: your age, height, weight, how much you work out, your waist size, heart rate, blood pressure, and it goes on. Then you press a button, you find out what your actual fitness age is.

“This kind of testing, an assessment of fitness age, is actually very valid and it helps us understand the benefits of being fit and healthy,” she added, explaining that anyone can use the online calculator for free.

Peeke, a board member of the organization that runs the National Senior Games, says many of the competitors didn’t start training until later in life. Consisting of a variety of sports — from track and field to triathlon — the games' average competitor is 68, although their average fitness age is 43.

"It doesn’t matter how old you are," she said. "Twenty, 25, 30 ... who cares, all of us can lower our fitness age by staying right on top of it, taking good care of ourselves, especially physical activity."

Peeke says it is never too early or too late to start reaping the benefits of exercise.