Walking Intensity and Step Count Are Linked to Health Benefits

Even a little walking may help avert serious illness and death, and a brisk stroll may be especially beneficial, according to a study of nearly 80,000 middle-aged and older adults.

Each additional 2,000 steps per day — up to 10,000 — was associated with 8% to 11% fewer deaths and less heart disease and cancer, the researchers found. Walking quickly had an even stronger link to lower health risks.

The findings were reported in JAMA Internal Medicine. In a separate paper, published in JAMA Neurology, the researchers reported associations between walking and reduced risk of dementia.

Moving Faster Provides a Health “Bonus”

The findings expand on evidence in smaller studies of middle-aged individuals and older women that suggested health benefits from covering less than the widely promoted target of 10,000 steps a day.

The new study supports the ideas that “every step counts” and moving faster provides a health “bonus,” said one of its co-lead authors, Borja del Pozo Cruz, PhD, an associate professor at the University of Southern Denmark, Odense, and a senior researcher in health at the University of Cadiz, Spain.

Del Pozo Cruz and his coauthors analyzed median daily step counts for 78,500 adults aged 40-79 years in the U.K. Biobank database who agreed to wear an accelerometer for 1 week. Participants’ average age was 61. Fifty-five percent were women and 97% were White.

Steps were categorized as “incidental,” defined as a pace of less than 40 per minute, and “purposeful,” ones taken at the pace of 40 or more per minute. Researchers also calculated peak 30-minute cadence, the average of an individual’s 30 most active minutes in a day.

Participants’ health records were reviewed after 7 years. Each additional 2,000 steps taken was associated with lower all-cause mortality, cardiovascular mortality, and cancer mortality.

Similar incremental reductions were observed in the incidence of heart disease, defined as fatal and nonfatal coronary heart disease, stroke, and heart failure; and a composite cancer outcome of 13 sites shown to be associated with low physical activity.

Both incidental and purposeful steps were linked to lower rates of mortality and disease. Particularly encouraging, the researchers said, was the benefit associated with incidental steps, which might be more feasible for some individuals than a planned walk.

The association with better outcomes was especially strong for peak-30 cadence, with individuals in the top fifth of intensity having a 34% lower mortality rate compared with those in the bottom fifth — an observation that researchers wrote “reflects the importance of the natural best effort relative to the individual’s capability.”

The analysis adjusted for a variety of factors including age, sex, race, smoking, alcohol use, fruit and vegetable consumption, medication use, family history of cardiovascular disease or cancer, and sleep quality. It also excluded participants who had deaths and illnesses within 2 years of a step assessment to minimize the problem of reverse causation, in which existing health problems cause participants to move less.

Data Contribute Evidence Toward Step Count Recommendations

The data are observational and do not prove cause and effect, the researchers noted. Still, the authors said the study “contributes critical evidence toward step count–based recommendations” for physical activity.

Guidelines of the United States and the World Health Organization recommend 150 minutes of moderately intense activity or 75 minutes of vigorous activity weekly plus strength training twice a week.

Given the proliferation of activity trackers in phones and watches, recommendations based on steps could be especially useful for individuals who don’t intentionally record their physical activity, the researchers wrote.

“It’s nice to have a study that puts some science behind steps counts,” cardiologist Nieca Goldberg, MD, a clinical associate professor of medicine at New York University, and a spokesperson for the American Heart Association, said of the findings.

Particularly important, said Goldberg, who was not involved in the study, is the lack of a minimum threshold for health benefits, since the 10,000-step target may be daunting for some individuals.

Only one in five participants in this latest study achieved 10,000 steps per day, according to the paper.

The authors wrote that promotion of lower step targets “may provide a more realistic and achievable goal for the general adult population,” and longevity gains “may be maximized simply by shifting away from the least-active end of the step-count distribution.”

Goldberg put it this way: “Take a walk. Try to aspire to 10,000 steps. But if you can only do 6,000 or 8,000, you get benefit there, too.”

Cathy Handy Marshall, MD, MPH, an assistant professor of oncology at Johns Hopkins University, Baltimore, who was not involved in the new study, said the findings can be used to guide “exercise prescriptions,” but more research is needed to tailor recommendations, particularly for individuals who cannot achieve high step counts.

Del Pozo Cruz said the findings need to be replicated in other populations.

source: https://www.medscape.com/viewarticle/980974