Americans over 40 could live five years longer if they were all as active as the top 25% of the population, modeling study shows

If every American over age 40 were as physically active as the top 25% of the population, they could live an average of five years longer, according to the findings of a modeling study. published online in the British Journal of Sports Medicine.

And if the least physically active were to match the levels of the most physically active, they could live almost eleven years longer, the estimates show.

It is known that low physical activity levels are associated with a higher risk of diseases, such as heart disease and stroke, as well as premature death, but it is not clear to what extent low physical activity levels shorten lifespan in specific groups of people or countries. , such as the US.

To find out, the researchers created a predictive model to estimate the impact of different levels of increased physical activity on life expectancy.

They based their model on estimates of physical activity risk derived from activity tracker data from the 2003-2006 National Health and Nutritional Examination Survey for people at least 40 years old, plus 2019 population data from the US Census Bureau and deaths recorded in 2017 from the National Center. for health statistics.

The total physical activity of the most active 25% of Americans over age 40 was equivalent to 160 minutes of walking at a normal pace at a speed of 4.8 km/(3 miles)/hour per day.

Based on this, the researchers estimate that if all over-40s in the US matched this level of physical activity every day, their average lifespan would increase by just over five years, raising life expectancy at birth from 78.6 to almost 84 year.

And if the least physically active 25% of the population matched the level of the most physically active 25%, they would need to walk an additional 111 minutes every day at 3 miles per hour (or an equivalent effort). But this could increase their life expectancy by almost eleven years, the estimates suggest.

The biggest life gains per hour of walking were seen among the least physically active people, for whom each additional hour of walking could add 376 minutes to their life expectancy – equivalent to around six hours. The gains in life expectancy decreased as physical activity increased and on average, each additional hour of walking could add 169 minutes (two hours and 49 minutes) to life expectancy.

This is an observational study and as such cannot establish cause and effect, and the researchers acknowledge several imitations of their findings. For example, the predictive model they used may have underestimated or overestimated the benefits of physical activity for Americans, because of the research results it relied on.

But they nevertheless suggest that increased investments in promoting physical activity and creating living environments that promote physical activity have the potential to yield large gains in life expectancy for Americans at the population and individual levels.

‘Our findings suggest that [physical activity] provides substantially greater health benefits than previously thought, which is due to the use of more precise measuring tools [it]”, they write.

“The greatest gains in ‘lifespan per hour’ of walking were seen for individuals in the lowest activity quartile, where an hour of walking could add an impressive six hours to life.”

But the researchers acknowledge that increasing physical activity at the population level is a complex task that requires a system-wide approach.

“Infrastructure measures that encourage active transportation, walkable neighborhoods, and green spaces may be promising approaches to increasing physical activity and resulting healthy life expectancy at the population level,” they suggest.