Is Climate Change Quietly Fueling a Global Physical Inactivity Crisis?

Rising temperatures could be making the global population less physically active, with consequences that could be catastrophic, according to a potentially landmark study published today in The Lancet Global Health.¹

The authors explain that physical activity is one of the world’s most pressing public health threats. Not only have one-third of all adults failed to meet World Health Organization (WHO) minimum physical activity recommendations²—either 150 minutes at moderate intensity of 75 minutes at vigorous intensity³—but the economic ramifications are staggering: the equivalent of US$14 billion in productivity losses, US$54 billion in direct annual health care costs, and 5% of all adult deaths. Despite these known burdens, the authors are unaware of any study to have quantified the relationship between long-term heat exposure and global physical activity levels, leaving policymakers without optimal tools to respond to the crisis.

Temperatures and Physical Inactivity

Their population-level panel study encompassed 156 countries, 3588 country-year observations, 507 population-based surveys, and 5.7 million adult participants (all 18 years and older) for 2000 through 2022. The primary outcome of interest was age-standardized prevalence of physical inactivity in adults per exposure to different temperature ranges.

“We converted projected physical inactivity into excess deaths and valued lost productivity using a friction-cost approach calibrated to each country’s gross domestic product and labor participation rates,” the authors wrote.

Overall, each extra month with a mean temperature above 27.8°C (82.0°F) conveyed a 1.44-percentage-point (95% CI, 0.49-2.39) increase in global physical inactivity but a 1.85-percentage-point increase among low-income and middle-income countries—indicating a stronger effect. The trend was echoed with an evident difference between women and men, showing the former to be more affected (1.69 [95% CI, 0.52-2.87] vs 1.18 [95% CI, 0.43-1.93] percentage points). This translates to 25.7% of adults for the study years not meeting the WHO physical activity recommendations, with a pronounced difference between women (22.2%) and men (29.0%) across temperatures that ranged from subzero to equatorial heat above 28.0°C (82.4°F). There was no discernible effect in high-income countries.

Mortality and Economic Projections

The investigators incorporated 3 climate-related shared socioeconomic pathway scenarios to project their findings out to 2050: low, intermediate, and high emissions. By that year, global physical inactivity is projected to increase by 0.98 percentage points (95%, 1.0-2.6) under the low-emissions scenario, 1.22 percentage points (95% CI, 2.0-4.5) under the intermediate-emissions scenario, and 1.75 percentage points (95% CI, 5.0-8.5) under the high-emissions scenario.

Particular regional hotspots are projected to be Central America, the Caribbean, eastern sub-Saharan Africa, and equatorial Southeast Asia—up to 4.0 percentage points—with the following consequences:

• 0.47 to 0.70 million additional premature deaths per year
• $2.40 billion to $3.68 billion in annual productivity losses

These figures could then represent 7.19 to 10.73 percentage points of all physical activity–attributable deaths (n = 6.52 million) and 5.12 to 7.85 percentage points of all physical activity–attributable productivity losses ($46.92 billion).

“Without stronger mitigation, rising temperatures alone could undermine—or even reverse—a substantial share of WHO’s target of cutting global physical inactivity by 15% by 2030,” the study authors wrote, “while simultaneously slowing economic growth through heat-related drops in worker productivity.”

Response to the Research

In the same issue of The Lancet Global Health, an editorial concurred with the significance of the authors’ findings and framed them within a broader context of providing “much needed and convincing evidence”⁴ by distinguishing between choice-based and necessity-based physical activity. These authors argued that populations in low- and middle-income countries face a sort of double jeopardy, with those forced to move for their work (eg, transportation-related movement or occupation) facing greater potential physical injury.

They call for research to move from solely identifying problems to building solutions, and they champion walkable urban design, green spaces, and active movement as strategies that simultaneously address inactivity and climate change, framing physical activity as a fundamental human right that policy must protect.

References

1. García-Witulski C, Rabassa M, Melo O, Sarmiento JH. Effects of climate change on physical inactivity: a panel data study across 156 countries from 2000 to 2022. Lancet Glob Health. 2026;14:e500-e511. https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(25)00472-3/abstract

2. Strain T, Flaxman S, Guthold R, et al. National, regional, and global trends in insufficient physical activity among adults from 2000 to 2022: a pooled analysis of 507 population-based surveys with 5.7 million participants. Lancet Glob Health. 2024;12(8):e1232-e1243. doi:10.1016/S2214-109X(24)00150-5

3. Global status report on physical activity 2022. World Health Organization. October 19, 2022. Accessed March 16, 2026. https://www.who.int/teams/health-promotion/physical-activity/global-status-report-on-physical-activity-2022

4. Ding D, Lee EY. Physical inactivity: another casualty of climate change. Lancet Glob Health. March 16, 2026.