While improved measurement techniques have strengthened the evidence linking low physical activity to higher mortality, this has not yet led to more accurate estimates of the disease burden caused by insufficient PA.
Griffith University researchers’ study aimed to quantify the impact of low physical activity on life expectancy, estimating how much life expectancy is reduced due to low physical activity and how much could be improved by increasing PA levels, both at the population level and for individuals.
This study used US-based accelerometry data to assess physical activity levels more accurately, bypassing the reliance on self-reported survey responses common in previous research. The findings revealed that the health benefits of physical activity were about twice as strong as previously estimated.
Specifically, the study found that the most active quarter of the population had a 73% lower risk of death than the least active quarter, highlighting the significant impact of higher physical activity on reducing mortality risk.
Lead researcher Professor Lennert Veerman said this cohort had the greatest potential for health gains.
“If you’re already very active or in that top quartile, an extra hour’s walk may not make much difference as you’ve, in a sense, already ‘maxxed out’ your benefit.”
“This is not an unreasonable prospect, as 25 percent of the population is already doing it.”
“It can be any exercise but roughly the equivalent of just under three hours of walking per day.”
The research team suggested that low levels of physical activity might have health impacts comparable to the negative effects of smoking. For instance, some studies have shown that each cigarette could shorten a smoker’s life by about 11 minutes.
Based on this comparison, the team emphasized that adopting a more active lifestyle could provide protective benefits against heart disease, stroke, certain cancers, and other chronic conditions. The study’s findings call for a revision of national physical activity guidelines, advocating for updated methods to better reflect the strong impact of physical activity on health and mortality.
Dr Veerman said physical activity had been vastly underestimated in its capacity to improve health outcomes, suggesting even modest increases in movement could lead to significant life-extension benefits.”
“If there’s something you could do to more than halve your risk of death, physical activity is enormously powerful.”
“If we could increase investment in promoting physical activity and creating living environments that promote it, such as walkable or cyclable neighborhoods and convenient, affordable public transport systems, we could increase longevity and reduce pressure on our health systems and the environment.”
Journal Reference:
- Lennert Veerman, Jakob Tarp et al. Physical activity and life expectancy: a life-table analysis. British Journal of Sports Medicine. DOI: 10.1136/bjsports-2024-108125