Research suggests that every extra hour of walking after the age of 40 increases your lifespan

As the latest research shows, the secret of longevity lies in the level of physical activity at the age of 40. Being more dynamic at this stage may extend your life.

The study found that Americans who augment their physical activity to match the top 25 percent of the population could extend their lives by five years. According to estimates, the least dynamic people can gain almost 11 years by reaching the activity level of the most dynamic test published in the British Journal of Sports Medicine.

To understand the impact of different levels of increased physical activity on life expectancy, researchers used a predictive model based on activity tracker data from the 2003–2006 National Health and Nutritional Examination Survey. Participants were 40 years of age and older.

The test found that the most dynamic 25 percent of Americans in this age group performed daily physical activity equivalent to 160 minutes of walking at a normal pace of 4.8 km (3 miles) per hour. The predictive model showed that if all Americans over 40 achieved this daily level of physical activity, their life expectancy would augment by more than five years. This means their life expectancy would augment from 78.6 years to approximately 84 years.

Meanwhile, when the least dynamic 25 percent of the population reached the activity level of the most dynamic 25 percent, they could gain almost 11 additional years of life. However, this would mean they would have to add 111 minutes of daily walking at a speed of 4.8 km/h, an equivalent effort.

“Our findings suggest that physical activity is associated with significant increases in life expectancy for individual Americans and the population as a whole. Moving the least dynamic 25% of the population over the age of 40 to the activity level of the top 25% could result in an expected life expectancy augment of approximately 11 years for this group. The greatest augment in life expectancy per hour of walking was observed among people in the lowest activity quartile, where an hour’s walk could add an impressive 6 hours to life,” the researchers wrote.

Although the greatest benefits were seen when there was an augment in physical activity in the least dynamic group, on average each additional hour of walking added about 3 hours (169 minutes) to life.

Because the study is observational and relies on a predictive model, there are several limitations. Scientists warn that there is a possibility that the benefits of physical activity may be “underestimated or overestimated.”