Rising Heat: Inactivity & Health Risks in Low-Income Countries

The image of an empty gym in rural Egypt speaks volumes about a looming, and profoundly inequitable, health crisis. A new study published in The Lancet Global Health isn’t just predicting a rise in sedentary lifestyles; it’s forecasting a surge in premature deaths and significant economic losses driven by climate change’s impact on physical activity. This isn’t a future problem – it’s a rapidly accelerating trend, and one that will disproportionately harm those least equipped to adapt.

For years, public health officials have stressed the importance of regular physical activity – at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity exercise weekly, as recommended by the WHO. However, this advice becomes increasingly difficult, and even dangerous, to follow as temperatures soar. The study highlights a critical, often overlooked, intersection between climate change and public health: the simple act of staying active is becoming physically impossible for millions.

The Deeper Context: A Vicious Cycle

This isn’t simply about discomfort. Physiologically, extreme heat strains the cardiovascular system, increases the risk of dehydration, and elevates perceived exertion, making even moderate activity feel exhausting. Compounding this, worsening air quality – a frequent companion to rising temperatures – further discourages outdoor exercise. The study’s findings build on a growing body of evidence linking climate change to a range of health problems, from heatstroke and kidney damage to the spread of infectious diseases.

The researchers, based in Argentina, Chile, Colombia, and Ecuador, meticulously analyzed self-reported data from 156 countries spanning 2000-2022. Their modeling reveals a particularly alarming trend: for every month spent above 27.8°C (82°F), physical activity is projected to decline by 4% in vulnerable regions. This decline is 1.85% in LMICs globally, significantly higher than the global average of 1.4%. The impact isn’t limited to leisure activities; it extends to occupational physical activity – impacting farmers, construction workers, and others whose livelihoods depend on physical labor – and active transportation like walking or cycling.

Looking Ahead: Adaptation and Mitigation are Key

The study’s implications are far-reaching. Beyond the direct health consequences and economic losses, a decline in physical activity creates a dangerous feedback loop. As people become more sedentary, they become more susceptible to chronic diseases, further straining healthcare systems already burdened by climate-related health challenges. The projected increase in air conditioning use, while offering temporary relief, could exacerbate the problem by encouraging even more indoor, sedentary behavior.

What’s next? The authors rightly emphasize the urgent need for proactive policies. Simply acknowledging the problem isn’t enough. Cities must prioritize “heat resilience” through measures like expanding green spaces and tree cover to provide shade, investing in cooling centers, and creating pedestrian- and cyclist-friendly infrastructure. Furthermore, recognizing physical activity as a “climate-sensitive necessity” – rather than a lifestyle choice – is crucial. This means integrating physical activity considerations into urban planning, public health initiatives, and climate adaptation strategies.

The example of the women’s gym in Egypt underscores the need for targeted interventions. Providing access to climate-controlled spaces for exercise, even in resource-constrained settings, can make a tangible difference. However, the larger challenge remains: addressing the root cause of the problem – climate change itself – through aggressive mitigation efforts to reduce greenhouse gas emissions. Without a concerted global effort to curb warming, the gains made in public health over decades could be rapidly eroded, leaving millions vulnerable to a future where even the simplest act of staying active becomes a health risk.

Sophia Samantaroy spent seven months in Egypt as a research fellow with the non-profit Coptic Orphans in 2025. She also contributes to Health Policy Watch as a reporter covering environmental health, chronic and infectious diseases, and US public health policy.

Image Credits: S. Samantaroy/HPW, WHO, The Lancet, The Lancet Global Health, Mario Spencer/Unsplash, The Lancet.