CHICAGO — He’s an 84-year-old diabetic with one lung that doesn’t work.

She’s his 84-year-old wife, a survivor of a nearly fatal aortic aneurysm.

About a dozen years ago, they stared old age in the face and made a decision. Instead of letting themselves go, they would get themselves going.

So, Stanley and Josephine Ewasiuk of Clearing, Ill., started attending exercise classes and walking in the park across the street from their house. Bit by bit, they got stronger.

Stanley couldn’t climb three steps without breathing heavily before he starting working out. “Today, I can climb a couple of dozen stairs, no problem,” he said.

After the surgery that saved her life, Josephine had to learn how to raise her right arm and maintain a sense of balance. “If you do something every day, it’s going to help,” she said, referring to her exercises.

Every Friday, the couple goes to yoga; Tuesday and Thursday, they’re off to a 45-minute exercise class at the Brookfield YMCA. In between are long walks in Hale Park at least twice a week.

“It helps my breathing, it keeps my blood sugar down, and I’m not taking as much medication,” said Stanley, whose diabetes has stabilized. “I can still work all day, when I want to. I feel like a kid yet.”

What’s aided the Ewasiuks can help anyone 65 or older, no matter how frail they may appear to be.

“All of the studies done so far indicate that it’s never too late to start exercising, and any amount of exercise is beneficial,” said Kelvin Davies, associate dean of the Leonard Davis School of Gerontology at the University of Southern California.

“We do lose strength and capacity as we age,” Davies said. “But by and large, the biggest losses are those that you see from people being inactive.”

Of course, the activity will depend on a senior’s circumstances. “When you’re in your 60s, you may want to go out for a vigorous 30- minute walk, while when you’re in your 90s, you might try to lift your legs in a wheelchair,” said Dr. Cheryl Phillips, president of the American Geriatrics Society.

“Start with something that’s fun,” she continued. “If you really don’t like what you’re doing, it’s not going to be sustainable no matter how good it is for you.”

Exercise isn’t the only way that seniors can stay healthier. Even if a person has smoked for decades, he or she will realize benefits within months of giving up the habit. Lung damage won’t be undone, but smoking’s impact on the heart will start to reverse, said Dr. William Dale, chief of geriatrics at the University of Chicago Medical Center.

“Eat fewer calories, eat more fruits and vegetables, and eat more slowly,” advised Dr. Robert Butler, president of the International Longevity Center in New York. “And throw in vitamin D, take your calcium and drink alcohol only in moderation.”

More advice: Don’t let yourself become isolated. Staying connected to other people is part of staying healthy, at any age.