Regular walking — even if below the minimum amount recommended by health officials — may help older adults live longer, according to a study published online in the American Journal of Preventive Medicine.

In fact, the study found that older adults who walked an average of only an hour a week had a 20 percent lower risk of premature death than those who did no exercise.

“Walking has been described as the ‘perfect exercise’ because it is simple, free, convenient, doesn’t require any special equipment or training, and can be done at any age,” said Alpa Patel, the study’s lead author and a cancer epidemiologist at the American Cancer Society, in a released statement.

“With the near doubling of adults aged 65 and older expected by 2030, clinicians should encourage patients to walk even if less than the recommended amount, especially as they age, for health and longevity,” she added

Current public health guidelines recommend that adults engage in at least 150 minutes of moderate-intensity physical activity, or 75 minutes of vigorous-intensity physical activity, each week. Those levels are associated with “substantial” health benefits, the guidelines point out, including a lower risk of dying prematurely from heart disease, stroke, type 2 diabetes, and breast and colon cancer.

Yet, just half of adults in the United States achieve that minimum level of exercise. Older adults are even less likely to do so. Only 42 percent of adults aged 65 to 74 and 28 percent of those aged 75 and older meet the guidelines, according to data from the Centers for Disease Control and Prevention.

Study details

For the new study, Patel and her colleagues decided to look specifically at one form of physical activity — walking — to see if it was associated with a reduced risk of early death among older adults.

The researchers used data collected from almost 140,000 people aged 60 and older who were participating in the Cancer Prevention Study II . Every two years, the participants filled out health surveys, which included questions about how much time they spent exercising each week and what form that exercise took.

The vast majority — about 95 percent — reported some walking, and almost half said walking was their only form of moderate- to vigorous-intensity exercise. A small percentage — 5.8 percent of men and 6.6 percent of women — said they engaged in no form of moderate- or vigorous-intensity exercise.

The participants were followed for 13 years (1999-2012). During that period, about 34,000 of them died.

Key findings

An analysis of all that data revealed that people who reported doing no regular physical activity at the start of the study were 26 percent more likely to have died than those who reported some activity — even if it was less than two hours a week.

Those who met or exceeded the minimum recommendations for physical activity (2.5 to 5 hours per week), on the other hand, were 20 percent less likely to have died during the study. And that included people for whom walking was their sole form of physical activity.

The findings held even after the researchers adjusted for smoking, obesity, chronic illness and other risk factors that raise the risk of premature death.

Walking-only was most strongly associated with lowering the risk of death from pneumonia, influenza and other respiratory illnesses. Older adults who walked for more than six hours a week, for example, were 35 percent less likely to die prematurely from such an illness.

Walking-only was also associated, however, with a 20 percent lower risk of early death from heart disease and a 9 percent lower risk of early death from cancer.

Limitations and implications

This study is able to show only a correlation, not a direct causal link, between regular walking and mortality. Other factors — ones not involving walking and not adjusted for in the study — might explain the results.

The study also relied on the participants’ descriptions of their exercise habits, which can be unreliable.

Still, as background information in the study points out, other research has reported that regular walking reduces the risk of early death, including a recent meta-analysis that found just three hours of walking per week lowered the risk by 11 percent.

And the walking doesn’t have to be fast-paced. In the current study, the average pace of the participants was three miles per hour, or a 20-minute mile.

“I hope this encourages people, especially older adults but really anyone who’s not engaging in a physical activity regimen, that they don’t have to go out and become a marathon runner,” Patel told Real Simple reporter Amanda MacMillan. “Going from nothing to something provides a tremendous health benefit to overall longevity, and simply meeting those guidelines can provide even more.”

FMI: The study can be read in full on the website of the American Journal of Preventive Medicine.