Early one morning about eight years ago, my mom, then just shy of 90, stood at the door of my home office and said that her left arm hurt between her shoulder and elbow. Scared she was having heart problems, I called our family doctor, who sent Mom for a full day of cardiac testing. One test required her to walk on a treadmill. The staff hovered, worried that she’d lose her balance and tumble off. The attention was unwarranted. She easily kept up and even had enough breath to inform her attendants: “You know, I work out with a personal trainer every week.” She still does.

Mom has always valued exercise, and I’m convinced — along with her doctors, who are backed by a strong body of research — that her longtime fitness habit has slowed her decline and kept her in generally good health. (That pain in her arm turned out to be nothing.)
Exercise is “the best medicine no one wants to do,” says Ronan Factora, a gerontologist at the Cleveland Clinic. Even tiny bites of fitness bring big rewards. A2011 study that aimed to figure out whether a low level of exercise could bring health benefits showed that even 15 minutes of walking a day can add three to five years of life.
“I tell my elderly patients that it doesn’t take very much exercise to benefit them,” Factora says. “We’re not talking about breaking a sweat. I’m not asking you to run a marathon. I’m just asking you to get up and move.”
People at any age benefit from exercise, he says, and the frailest residents in nursing homes benefit the most.
Exercise helps keeps aging bodies healthy by increasing blood flow to the brain, carrying extra oxygen and other nutrients. It also helps keep blood pressure and blood sugar at normal levels, lowering the risk for vascular dementia, Factora says.
Exercise can also lower risk for dementia by keeping the hippocampus — the place in the brain where we make and store memories — a healthy size, according to some research. As we age, the hippocampus shrinks, raising our risk for dementia. In a study published in 2010, researchers tested aerobic exercise on 120 healthy adults. After one year, the hippocampus increased in volume by 2 percent in the group participating in aerobic exercise — “effectively reversing age-related loss in volume” by one to two years, according to the researchers. The volume declined in control-group, members, who were not asked to do aerobic training.
Even frail people with dementia benefit from exercise. According to a new review by the Cochrane Collaboration, eight clinical trials found that people with dementia who exercised improved their performance on tests used to evaluate memory loss. The reviewers expressed cautious optimism about the results, noting that there were differences in results from individual trials and that there was not enough evidence to show that exercise improves symptoms of depression. “Nevertheless, these are encouraging results, as dementia is a debilitating disease that results in progressive decline in cognition and ability to perform” daily activities.
Frailty itself should not keep those with cognitive impairment out of the gym. Researchers at the University of Heidelberg showed recently that people with dementia can be taught to use exercise machines and that the exercise done by people in this group can indeed be rigorous. And these workouts can help them both physically and mentally,
Everyone has limits, and it’s always best to start slowly, but “move from zero to something,” Factora says. He suggests having someone such as a physical therapist help monitor progress at first. Then move to a personal trainer and exercise on a regular schedule.