Walking more than 2 hours a day may add years to life expectancy for middle-aged adults

Key takeaways:

• Adults aged older than 40 years would need to walk 160 minutes at 4.8 km an hour daily to boost life expectancy.
• An extra hour’s walk among the least active adults could add 376.3 minutes of life expectancy.

Adults aged older than 40 years could extend their life expectancy by over 5 years if they matched the physical activity of that of the most active 25% of the U.S. population, a study showed.

Moreover, the least physically active adults could live nearly 11 years longer if they were as active as the top 25% of the population.

The health benefits of exercise, particularly in the form of walking, have been well established, with prior research tying walking to weight management, improved cardiovascular and neurological health, lower mortality risk and reduced disease burden.

However, a significant limitation of past studies is that physical activity levels are often self-reported, which “may lead to underestimation of the effect of physical activity on morbidity and mortality,” Lennert Veerman, a professor of public health at Griffith University in Australia, and colleagues wrote in the British Journal of Sports Medicine.

Their study created a predictive model to assess the effects of different physical activity levels on life expectancy.

The model was based on physical activity risk estimates from device-measured data belonging to adults aged 40 years or older from the 2003 to 2006 National Health and Nutritional Examination Survey.

Additionally, researchers used 2019 population data from the U.S. Census Bureau and 2017 mortality data from the National Center for Health Statistics to develop the model.

The total physical activity of the most active 25% of the population was equivalent to 160 minutes of walking at 4.8 km, or almost 3 miles, an hour every day.

Veerman and colleagues found that all adults aged older than 40 years could live an extra 5.3 years (95% uncertainty interval [UI], 3.7-6.8) on average if they engaged in the same level of activity as the top 25% of the population, increasing life expectancy at birth from 78.6 years to 83.7 years.

Meanwhile, the least physically active adults would need to walk an extra 111.2 minutes at 4.8 km an hour a day to match the activity levels of the top 25% most active. This would increase life expectancy by 10.9 years (95% UI, 9.3-12.7).

The greatest gain in life expectancy was seen among the least active adults, among whom an additional hour’s walk would add 376.3 minutes — or 6.3 hours — of life expectancy. Each extra hour of physical activity, meanwhile, would extend life by an average of an average of 169.1 minutes.

Study limitations identified by the researchers included potential overestimation of associations between physical activity and mortality. They also could not determine causality because of the analysis’ observational design. Boosting physical activity at the population level is a “complex task that requires a systems-based approach,” Veerman and colleagues wrote. “Infrastructure measures that encourage active transport, walkable neighborhoods as well and green spaces might be promising approaches to increase physical activity and resultant healthy life expectancy at the population level.”

References:

• US over 40s could live extra 5 years if they were all as active as top 25% of population. Available at: https://bmjgroup.com/us-over-40s-could-live-extra-5-years-if-they-were-all-as-active-as-top-25-of-population/. Published Nov. 14, 2024. Accessed Nov. 21, 2024.
• Veerman L, et al. Br J Sports Med. 2024;doi:10.1136/bjsports-2024-108125.