Not even pollution stops exercise as 'the best medicine'

Physical activity continues to be a key tool for health, even in urban environments with high levels of air pollution. This is the conclusion of a study led by researchers from the Virgen del Rocío University Hospital in Sevilla, which analyzes whether the benefits of exercise outweigh the risks of breathing polluted air during its practice.

The study, published in the journal Open Respiratory Archives, included participation from Pilar Cejudo, from the Seville Biomedicine Institute (IBIS) and the Ciberes of the Carlos III Health Institute. Initial data indicates that one in three adults and 81% of adolescents do not engage in enough physical activity, while about 90% of the world's population breathes air with pollution levels above recommended standards. This dual problem poses a "physiological paradigm" for public health.

The authors explain that performing exercise in polluted urban environments can have short-term negative effects, especially on the cardiopulmonary system. Physical activity increases ventilation and leads to more mouth breathing, which reduces the natural filtering capacity of the respiratory tract. This facilitates the entry of fine particles and harmful gases into the lungs, increasing inflammation, oxidative stress, and symptoms like coughing or chest tightness.

Moreover, the dose of pollutants inhaled can increase up to four times during exercise, especially if it is intense or prolonged. Sessions longer than two hours in poor air quality conditions are associated with a decrease in lung function and an increase in inflammation of the respiratory tract.

However, the study maintains that the benefits of physical exercise generally outweigh the harmful effects of pollution. In fact, while exposure to polluted air increases the risk of mortality by about 36%, exercising reduces it by 26% even under those conditions (compared to 31% in clean air). The impact is particularly significant in people with chronic respiratory diseases, such as COPD or asthma.

In these patients, pollution not only worsens respiratory symptoms and increases the risk of hospitalization, but also discourages physical activity, creating a "vicious cycle" of dyspnea and inactivity that deteriorates their health.

Given this scenario, the researchers emphasize that the solution is not to stop exercising, but to practice it more safely. Among the recommendations, they highlight limiting sessions to less than one hour when air quality is poor, avoiding peak traffic hours, prioritizing green spaces or pedestrian zones, and opting for strength exercises or indoor activities on days with high pollution. They also advise using real-time air quality monitoring apps.