A new study published in the American Journal of Preventive Medicine suggests that even a little walking can significantly reduce mortality risk, compared with inactivity.
The Physical Activity Guidelines for Americans recommend that adults engage in at least 150 minutes of moderate physical activity, or 75 minutes of intense physical activity, each week to reap "substantial" health benefits.
The Guidelines also emphasize the fact that "some physical activity is better than none" — and a new study further strengthens this message.
The research, led by Alpa V. Patel, Ph.D., strategic director of the Cancer Prevention Study-3 for the American Cancer Society (ACS), focuses on the most common and accessible form of physical activity: walking.
The study found that even levels of walking that do not meet the national recommendations still lower the risk of premature death by a considerable amount.
Studying the benefits of walking
Dr. Patel and her research team examined data from almost 140,000 people who took part in the Cancer Prevention Study II Nutrition Cohort. Of the participants, 6–7 percent said that they did not take part in any moderate or vigorous physical activity at the beginning of the study.
As many as 95 percent of the remaining participants said that they did some walking, and for almost half of them, walking was the only type of moderate to vigorous physical activity they engaged in.
The team adjusted for other risk factors that might have influenced the results, such as obesity, smoking, and chronic illnesses.
Dr. Patel spoke to Medical News Today about the strengths and limitations of her study, saying, "The strengths of this study are its large sample size, [the] large proportion or participants who exclusively walked for exercise, and our ability to consider many potential confounding factors."
"Limitations," she added, "include [the fact] that data were self-reported, limited information on walking pace, and lack of occupational data." However, Dr. Patel also noted that these limitations were adequately addressed by her team.
Walkers at lower risk of all-cause mortality
The study revealed that, compared with no physical activity at all, as little as under 2 weekly hours of walking correlated with a lower risk of all-cause mortality.
Additionally, meeting or exceeding the national guidelines for physical activity by twofold through walking alone was linked with a 20 percent decrease in mortality risk.
The difference in outcomes between those who met the recommendations and those who exceeded them was minimal.
Walking seemed to do the most good for preventing respiratory disease-related mortality. More specifically, more than 6 hours of weekly walking was associated with a 35 percent lower risk in this type of mortality, compared with those who were the least physically active.
Cardiovascular mortality was also lower among those whose only form of physical activity was walking. These people were 20 percent less likely to die from a cardiovascular illness and 9 percent less likely to die of cancer.
Dr. Patel shared with MNT some directions for future research. "Replication of these findings in other large population studies," she said, "will provide additional evidence on the benefits of walking for health and longevity."
She added that the researchers "are also interested in further understanding the association between walking and the risk of developing diseases like cancer."
Walking is the 'perfect exercise'
On the study's findings, Dr. Patel told MNT that she and her colleagues were "rather pleased as they are what [they] hoped for."
"Walking," she continued, "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."
"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."
Alpa V. Patel, Ph.D.
National surveys show that only half of all the people in the United States meet the Guidelines' recommendations, with seniors being even less likely to follow them.
Almost 27 percent of people aged 65 to 74 and over a quarter of the population aged 50 to 64 said that they are inactive, according to a survey recently carried out by the Centers for Disease Control and Prevention (CDC.)
"[Our] findings," Dr. Patel explained to MNT, "are encouraging for the many individuals who do not currently engage in a physical activity regimen as they can achieve tremendous health benefits from simply walking."