Cardiologue et Directeur de la prévention, Institut de Cardiologie de Montréal. Professeur titulaire de clinique, Faculté de médecine de l'Université de Montréal. / Cardiologist and Director of Prevention, Montreal Heart Institute. Clinical Professor, Faculty of Medicine, University of Montreal.See all articles
Several studies have shown that regular walking, particularly at 8,000 steps/day or more, reduces the risk of premature mortality. 8,000 steps is equivalent to about 5 km or 1 hour 15 minutes of walking, depending on the length of each step and walking speed. In a recent study, researchers from Japan and the United States wondered what the optimal frequency is to benefit from the positive effects of walking on longevity. In other words, is it necessary to walk as many as 8,000 steps every day of the week or could a few days a week be enough to obtain the maximum health benefits?
The 3,101 adult participants in a US cohort study (National Health and Nutrition Examination Surveys (NHANES), 2005–2006) were divided into three groups based on the number of days per week they walked 8,000 steps or more (0 days, 1-2 days, and 3-7 days). The number of steps walked daily was measured by an accelerometer worn by each participant for a week at the start of the 10-year study.
- 632 (20%) participants walked fewer than 8,000 steps on each of the 7 days of the week.
- 532 (17%) participants walked 8,000 steps or more 1-2 days a week.
- 1937 (63%) participants walked 8,000 steps or more 3 to 7 days a week.
During the 10 years of follow-up, there were 439 deaths (all-cause mortality), including 148 deaths from cardiovascular disease. Compared to participants who walked fewer than 8,000 steps/day every day of the week, those who walked 8,000 steps or more 1-2 days per week or 3-7 days per week had a lower risk of all-cause mortality of 14.9 and 16.5%, respectively. The risk of mortality from cardiovascular disease was 8.1% lower in participants who walked 8,000 steps or more 1 or 2 days per week and 8.4% lower in participants who walked 8,000 steps or more 3 at 7 days a week.
The dose-response association for all-cause and cardiovascular mortality was curvilinear, i.e., the positive association reaches a plateau at 3 days per week. Furthermore, sensitivity analyses using a lower threshold (6,000 steps/day) or a higher one (10,000 steps/day) gave similar results. Age-stratified analyses indicate that participants under 65 years of age who walked 8,000 steps daily 1 to 2 days or 3 to 7 days per week had a lower risk (-7.4% and -7.8%, respectively) of premature mortality (-19.9% and -27.7% for participants aged 65 years and older), compared to participants who walked fewer than 8,000 steps/day every day of the week. Analyses by sex indicate reductions in the risk of all-cause mortality in both sexes: slightly less in women (-11.6% and -12.2% for 1-2 days and 3-7 days with over 8,000 steps daily per week) than in men (-20.8% and -23.8%).
The results of this study suggest that it is possible to obtain substantial health benefits from walking only a few days a week. This is great news for people who cannot exercise regularly, for example because of work or family obligations.