Higher temperatures are linked to more physical inactivity

What the study found: Rising temperatures were associated with higher physical inactivity among adults, and the study projected further increases by 2050. The authors also estimated additional deaths and productivity losses linked to those projected increases.
Why the authors say this matters: The authors conclude that rising temperatures may add to health and economic burdens, especially in tropical regions, and they say heat-adaptive urban design, subsidised climate-controlled exercise facilities, targeted heat-risk communication, and emissions reductions are needed.
What the researchers tested: The researchers analysed data from 156 countries from 2000 to 2022 using a binned fixed-effects panel regression model. They examined the relationship between age-standardised physical inactivity in adults aged 18 years and older and annual exposure to different temperature ranges, then used climate projections under different shared socioeconomic pathways (SSPs) to forecast future inactivity, deaths, and productivity losses.
What worked and what didn't: Each additional month with a mean temperature above 27.8°C was associated with a 1.44 percentage-point increase in physical inactivity globally and a 1.85 percentage-point increase in low-income and middle-income countries. By 2050, projected increases in physical inactivity ranged from 0.98 to 1.75 percentage points depending on the SSP, with hotspots above 4 percentage points in Central America, the Caribbean, eastern sub-Saharan Africa, and equatorial southeast Asia; these changes were estimated to correspond to 0.47-0.70 million additional deaths and Intl$2.40-3.68 billion in annual productivity losses.
What to keep in mind: The abstract does not describe study limitations beyond the observational and projection-based design. The projections depend on the climate and risk assumptions used in the analysis.

Key points

• In 156 countries, higher monthly heat exposure was associated with more physical inactivity in adults.
• A mean temperature above 27.8°C for one additional month was linked to a 1.44 percentage-point rise in inactivity globally.
• The projected increase in inactivity by 2050 ranged from 0.98 to 1.75 percentage points depending on the SSP scenario.
• The largest projected hotspots were in Central America, the Caribbean, eastern sub-Saharan Africa, and equatorial southeast Asia.
• The authors estimated 0.47-0.70 million additional deaths and Intl$2.40-3.68 billion in annual productivity losses by 2050.