Physical inactivity (PA) is considered the fourth top risk factor for death worldwide. Approximately 3.2 million of world’s population die each year due to insufficient PA. On a global scale, every fourth adult do not achieve the minimum recommended level of 150 min of moderate intensity or 75 min of vigorous intensity PA per week. Environmental factors, such as air pollution, heavy metals, pesticides, and traffic noise, are recognized as endocrine disruptors causing cardiometabolic disease such as type 2 diabetes. The World Health Organization (WHO) concludes that air pollution is a major contributor to the global burden of disease, with 9 out of 10 people worldwide breathing polluted air, exceeding the WHO guideline values for ambient air quality. PA influences the uptake and deposit of air pollutants in the lungs and airways due to increased breathing frequency and minute ventilation. These circumstances raise a key question-should exercise be encouraged in areas with polluted air? Hence, determining the tradeoff between the health benefits of PA and the potential harmful effects of increased exposure to air pollution is an ongoing target.

Oxidative stress and inflammation represent the common denominator of the adverse cardiorespiratory health effects of air pollution. For a long time, O₃ was the main focus of air pollution research, and only recently has PM 2.5 taken its place. PM, especially PM 2.5, is now known to influence the onset and progression of cardiovascular disease, mainly through oxidative stress and inflammation pathways. Muscular exercise has long been known to cause the formation of reactive oxygen species (ROS), which initially seems somewhat incongruent to the well documented benefits to health. But increasing PA above 1000 MET-min/week is associated with increased risk of cardiovascular disease among subjects exposed to high levels of PM 2.5 indicating that greater volume of physical activity may adversely affect cardiovascular health in areas where high air pollution is prevalent.

Association has been found through numerous studies between increased PA and access to, and use of, green space among senior citizen, working adults, and children. The availability of green space has also been associated with reduced prevalence of obesity and type 2 diabetes, reduced cardiovascular morbidity and mortality, improved mental health and cognitive function, improved pregnancy outcomes, and overall reduced mortality and increased life span. Personal protection measures are the only way to decrease air pollutant exposure during this transition process. Several clinical field studies demonstrated that prevention of PM 2.5 exposure by N95 filtration masks prevents the increase in systolic blood pressure, induced by particle exposure, and has beneficial effects on heart rate variability. Exercising in green space areas or even rural places, represents another mitigation strategy for the individual to prevent high exposure levels of air pollutants. Dietary fish oil administration partially prevents PM 2.5 dependent induction of inflammation, oxidative stress, and neuroendocrine stress response. Nevertheless, further research is urgently needed to determine the exact thresholds of exercise volume specially when harmful environmental exposures become inevitable.