Experts recommend getting at least 30 minutes a day of moderate physical activity, such as walking.
3.2 million. That is the number of annual deaths worldwide caused by lack of physical activity, according to the World Health Organization (WHO). However, an achievable goal, such as walking 8,000 steps one or two days a week – about 4 miles – could reduce the risk of death by 14.9 percent, according to a Kyoto University study. (Japan) and the University of California at Los Angeles (United States).
Experts recommend getting at least 30 minutes a day of moderate physical activity, such as walking. Some doctors recommend taking 10,000 steps a day, but more and more studies indicate that step goals should be adapted to each person’s age and physical condition.
Many studies have used daily step counting as a simple and reliable metric of physical activity and have explored the correlation between daily step counts and various health outcomes, such as dementia and cardiovascular disease.
This new meta-analysis, published in the scientific journal ‘JAMA Network Open’, has shown an association between an increase in daily steps and a gradual reduction in the risk of mortality. This association is maintained until a threshold of approximately 8,000 steps per day is reached, beyond which the risk of mortality remains constant.
In the study, the researchers evaluated the correlation between death rates in adults and the time they spend in physical activity, specifically taking 8,000 steps or more per day.
The study used data from the US National Health and Nutrition Survey, conducted in 2005 and 2006, which was later linked to the National Death Index through 2019. Of the total sample of 4,372 people age 20 and older, 3,120 participants had data on the use of an accelerometer for at least four days, which was used to calculate their daily step count.
From 2005 to 2006, the survey asked its participants to wear a waist-mounted accelerometer during waking hours for seven days. The study consisted of recording the number of steps during 60-second intervals each day.
To assess weekly step patterns, the study enrolled participants who had a minimum of four days with at least 10 hours of wear time, during which the accelerometer recorded step counts. Participants were classified into three groups based on how often they reached a minimum of 8,000 steps per week: zero days, one to two days, and three to seven days.
The average number of steps per day was almost 8,793. The study revealed that, of the total number of participants, 632 people reported taking 8,000 steps or more on zero days a week, while 532 took 8,000 steps or more on one to two days a week.
In addition, 1,937 participants reported taking 8,000 steps or more three to seven days a week. People who took 8,000 or more steps a week were younger, male, Hispanic, with health insurance, married and non-smokers.
In addition, they were less likely to report obesity, statin use, comorbidities, or rate their health as fair or poor, compared with those who took less than 8,000 steps on fewer days a week.
During ten years of observation, 439 deaths from various causes and 148 deaths specifically attributed to cardiovascular diseases were detected.
After controlling for potential confounding variables, people who took 8,000 steps or more on one to two days per week and three to seven days per week were found to have a 14.9 and 16.5 percent reduced risk of 10-year all-cause mortality, respectively, compared with those who did not.
In addition, those who were physically active taking 8,000 steps or more one to two days per week and three to seven days per week had a 10-year cardiovascular mortality risk reduction of 8.1 and 8.4 percent, respectively, compared to those who did not.
The study also found that people in both younger and older age groups had a lower 10-year risk of all-cause mortality when they reported taking 8,000 steps or more on one to two days per week or three to seven days per week, compared with those who did not engage in any physical activity zero days per week.
Specifically, people 65 and older were 19.9 percent less likely to die if they took 8,000 steps once or twice a week, while those under 65 experienced a 7.4 percent reduction in the risk of death.
In addition, those who were physically active by taking 10,000 steps or more on one to two days per week had a 10-year adjusted risk of death from all causes of 8.1 percent. In contrast, those who reported taking 10,000 steps or more three to seven days a week had a 7.3 percent lower risk, while those who reported taking 10,000 steps zero days a week had a risk of 16. 7 percent. M.T.T./ L.D.B. (SyM)