Taking 8,000 steps or more for just 1 or 2 days a week was linked to a significant reduction in all-cause and cardiovascular mortality, according to a study of about 3,000 adults.
Previous research has shown lower mortality rates among individuals who walk consistently, especially those who log at least 8,000 steps daily, but the benefit of intense walking just once or twice a week on long-term health outcomes has not been examined, wrote Kosuke Inoue, MD, of Kyoto University, Japan, and colleagues.
In a study published in JAMA Network Open, the researchers reviewed 10-year follow-up data for 3,101 adults aged 20 years and older who were part of the 2005 and 2006 National Health and Nutrition Examination Survey (NHANES).
The participants were asked to wear accelerometers to track their steps for 7 consecutive days. The researchers assessed the dose-response relationship between days of taking 8,000 steps or more (about 4 miles) during 1 week, and the primary outcome of all-cause mortality risk after 10 years. Cardiovascular mortality risk after 10 years was a secondary outcome.
The mean age of the participants was 50.5 years and 51% were women. The breakdown by ethnicity was 51% White, 21% Black, 24% Hispanic, and 4% other races/ethnicities. A total of 632 individuals took 8,000 steps or more 0 days a week, 532 took at least 8,000 steps 1-2 days per week, and 1,937 took at least 8,000 steps 3-7 days a week.
During the 10-year follow-up period, overall all-cause mortality was 14.2% and cardiovascular mortality was 5.3% across all step groups.
In an adjusted analysis, individuals who took at least 8,000 steps 1-2 days a week had a 14.9% lower all-cause mortality risk compared with those who never reached 8,000 daily steps. This difference was similar to the 16.5% reduced mortality risk for those who took at least 8,000 steps 3-7 days a week.
Similarly, compared with the group with no days of at least 8,000 steps, cardiovascular mortality risk was 8.1% lower for those who took 8,000 steps 1-2 days per week and 8.4% lower for those who took at least 8,000 steps 3-7 days per week. The decreased mortality risk plateaued at 3-4 days.
These patterns in reduced all-cause mortality risk persisted in a stratified analysis by age (younger than 65 years and 65 years and older) and sex. Similar patterns in reduced mortality also emerged when the researchers used different thresholds of daily steps, such as a minimum of 10,000 steps instead of 8,000. The adjusted all-cause mortality for groups who took at least 10,000 steps 1-2 days a week, 3-7 days a week, and no days a week were 8.1%, 7.3%, and 16.7%, respectively, with corresponding cardiovascular mortality risks of 2.4%, 2.3%, and 7.0%, respectively.
“Given the simplicity and ease of counting daily steps, our findings indicate that the recommended number of steps taken on as few as 1 to 2 days per week may be a feasible option for individuals who are striving to achieve some health benefits through adhering to a recommended daily step count but are unable to accomplish this on a daily basis,” the researchers wrote in their discussion.
The findings were limited by several factors including the use daily step measures for 1 week only at baseline, with no data on how physical activity changes might impact mortality risk, the researchers noted. Other limitations included possible accelerometer error and misclassification of activity, possible selection bias, and lack of data on cause-specific mortality outside of cardiovascular death, they said.
However, the results were strengthened by the use of accelerometers as objective measures of activity and by the availability of 10-year follow-up data for nearly 100% of the participants, they said.
“Although our findings might suffer from residual confounding that should be addressed in future research, they suggest that people may receive substantial health benefits even if a sufficient number of steps are taken on only a couple days of the week,” they concluded.
Proceed with caution
The current study findings should be interpreted cautiously in light of the potential unmeasured confounding factors and selection bias that often occur in studies of physical activity, James Sawalla Guseh, MD, of Massachusetts General Hospital, and Jose F. Figueroa, MD, of Harvard T.H. Chan School of Public Health, Boston, wrote in an accompanying editorial.
The results support previous studies showing some longevity benefits with “weekend warrior” patterns of intense physical activity for only a couple of days; however, “the body of evidence for sporadic activity is not as robust as the evidence for sustained and regular aerobic activity,” the authors emphasized.
The editorial authors also highlighted the limitations of the current study, including the observational design and significant differences in demographics and comorbidities between the 1- to 2-days of 8,000 steps exercise group and the 0-day group, as well as the reliance on only a week’s worth of data to infer 10 years’ mortality.
Although the data are consistent with previous observations that increased exercise volume reduces mortality, more research is needed, as the current study findings may not reflect other dimensions of health, including neurological health, they said.
Despite the need for cautious interpretation of the results, the current study “supports the emerging and popular idea that step counting, which does not require consideration of exercise duration or intensity, can offer guidance toward robust and favorable health outcomes,” and may inform step-based activity goals to improve public health, the editorialists wrote.
The study was supported by the Japan Agency for Medical Research and Development, the Japan Society for the Promotion of Science, the Japan Endocrine Society, and the Meiji Yasuda Life Foundation of Health and Welfare. Dr. Inoue also was supported by the Program for the Development of Next-Generation Leading Scientists With Global Insight sponsored by the Ministry of Education, Culture, Sports, Science and Technology, Japan. The other researchers had no relevant financial conflicts to disclose. The editorial authors had no financial conflicts to disclose.
This story originally appeared on MDedge.com, part of the Medscape Professional Network.
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