Aerobic exercise and endurance training contribute to longevity and well-being. However, many urban American citizens who exercise outdoors are subject to air pollutants, such as automobile emissions and other dangerous particles.
Particles and gases, mostly from fuel combustion, float in the air in an almost transparent form. Higher concentrations of these potential cancer-causing free radicals can be seen as a type of haze or smog. These particles are a mixture of chemical solids and liquids with varying textures.
When people exercise while breathing polluted air, poisonous particles become trapped in the lungs. This causes the person to breathe slower and deeper, thus concentrating the levels of free radicals in the lungs even more. If more air is taken in through the mouth than through the nose, the lack of filtration through the nose allows a greater portion of gases to enter into the lungs. Particles captured in the lungs of runners who exercise near busy roads almost number the same amount of particles found in the lungs of smokers.
Exercise is crucial for preventing disease and other disorders; however, exercising in polluted environments can be counterproductive. Parks and other areas of recreation located away from heavy traffic are good alternatives to areas with high traffic. If parks are not easily accessible, exercising during low-peak traffic times may be a good alternative to exercising during high-peak traffic times.