Exercising in polluted air can increase the risk of asthma, heart attack and stroke. But is avoiding a workout any better?

Rather than exercise outside on bad-air days, many people choose to go to a gym, use a treadmill or skip the workout altogether. Those options work most of the time, but what about when a person must choose between canceling a long awaited sporting event or a bicycle trip because of the air quality index? In situations such as these, is exercising in polluted air worse than not exercising at all?

That is a question that scientist are currently researching. There are early indications that the potent anti-inflammatory effects of frequent exercise actually neutralize the damage caused by air pollution. It sounds counterintuitive: Exercise means breathing deeper, which means more particles bypass the nasal filtering and lodge lower down in the airway. But recent studies suggest exercise may actually offset the negative effects of breathing polluted air.

Using epidemiological data, Netherlands’ researchers recently discovered the air-pollution effects of changing from a car to a bicycle for quick trips in air-polluted municipalities would subtract between 0.8 and forty days from a person’s average life span. However, the extra exercise would prolong that person’s average life span by three to fourteen months.

All activity is beneficial, but exercising outdoors has been proven to have the added benefit of affecting a person’s mental wellbeing. Exercise helps to reduce stress, relieve anxiety and depression. Exercising outside in the fresh air and sunshine can give an added boost to a person’s overall sense of wellbeing.

The health benefits of exercise appear to outweigh any added risk. Of course, not everyone suffers or benefits equally. Genetics play a major role in a person’s health, so individuals and their doctors should take that into account when determining the pros and cons of outdoor exercise, especially during days when the air quality index is high.