In all her years of presentations, physical therapist Dale Avers has yet to see a hand raised when she asks audiences who aspires to live in a nursing home.

People fill conference rooms to hear Avers explain how to avoid ending up in nursing homes. The key, she says, is a healthy brain. And the key to a healthy brain is exercise.

Our brains, which continue to generate new brain cells even in our senior years, demand 25 percent of the blood and nutrients from every beat of our hearts. So, increasing our heart rate increases blood flow to the brain.

We increase our heart rate through aerobic exercise that is strenuous, that makes us sweat for at least 15 or 20 minutes at a time. We don't have to run marathons; we can take stairs instead of escalators, park far away rather than near. But when a particular exercise is no longer challenging, Avers says it's time to make it more challenging -- or try something new.

"The more you do, the more benefits you're going to reap," Avers says. People who exercise fewer than three times a week, compared with those who exercise more than three times a week, are dramatically more likely to develop Alzheimer's disease, which affects 50 percent of the people over age 85.

Mental stimulation is also important in maintaining brain health, she says.

"Easy, to me, is a four-letter word. Things that are easy are not good for us.

"Somehow, as we get older we feel entitled to take things easy -- and that's the worst thing we can do."

Crossword puzzles that are easy aren't stimulating.

Walking around a flat track isn't as beneficial as walking through hilly neighborhoods.

Avers -- a regular speaker at Health Link -- suggests audience members ask themselves: "What have I quit doing because it was too tough?"

Sometimes as people become hard of hearing, they give up trying to understand a conversation. Sometimes as people age, they become reluctant to pursue new fields of study. Instead, they go easy.

"You've got to change your belief that easy is good," Avers says.