The 2016 Summer Olympics in Rio de Janeiro, Brazil, have focused world attention once again on the potential impact of poor air quality on athletic performance. This was also the case for previous Olympic games in London and Beijing.

In Brazil, the biggest air pollution problem is ethanol. Ethanol represents about 40% of all fuel burned by automobiles in Brazil. As a result, Rio, like other Brazilian cities, suffers from unhealthy levels of ozone air pollution fueled by ethanol combustion. In some Rio neighborhoods, ozone levels are healthy only one out of every five days. And summer ozone levels are the highest of all. That has athletes concerned.

Concern over performance

Scientists have known for years that air pollution can reduce athletic performance and even put athletes’ health at risk. One important reason why is that during training athletes typically take in as much as 20 times more air than a person at rest. That means they are being exposed to 20 times more pollutants as well.

Several controlled studies with athletes have shown that exercise while breathing elevated levels of sulfur dioxide and ozone – major components of air pollution – can cause a constriction of the airways in the lungs. This has a direct impact on athletic performance.

One study of air pollution and marathon performance concluded that every increase of 10 mg per cubic meter of PM10 air pollution can be expected to decrease marathon performance by 1.4%. In situations such as Olympic events in which victory is measured in milliseconds and millimeters, air pollution can ultimately determine who wins or loses, as well as whether or not records are set.

Concern over health

While the effect of air pollution on athletic performance is a concern, the impact of air pollution on the short- and long-term health of athletes may be an even greater problem. One concern is that elite endurance athletes, especially those who are regularly exposed to airborne pollutants, are at risk of developing upper and lower airway dysfunction.

Studies have shown that a combination of dehydration and the inhalation of noxious air pollutants by endurance athletes may lead to the onset of asthma. Another concern is that exposure to pollutants can lead to airway hyperresponsiveness (AHR), a condition associated not only with asthma but also with chronic obstructive pulmonary disease (COPD).

The long-term consequences of athlete exposure to particle pollution in particular is also a concern. Studies show that people who live in areas with high levels of particle air pollution – specifically, airborne soot – are far more likely to die of heart attacks. Physicians who specialize in treating athletes says this is a concern for endurance athletes who take in very high doses of particle pollutants while training outdoors.

Steps athletes can take

In a perfect world, athletes would live and train only in geographic areas that are free of significant air pollution. But in reality athletes generally live and train near population centers where air pollution can threaten their performance and health. And endurance athletes (for example, long-distance runners and cyclists) often train near or alongside roadways, where combustion-pollutant levels are highest.

By taking a few steps to reduce inhalation of pollutants during training, recovery and competition, athletes may improve their health and performance – or at least reduce their risk of exposure to pollution. Here are a few tips:

• Opt for early morning and late evening workouts. When air pollution, especially ozone, is highest, limit outdoor workouts (running, swimming, cycling, rowing, etc.) to the early morning or late evening hours, when levels are significantly lower.
• Monitor air pollution levels. Keep an eye on local air quality warnings, especially during hot weather. Athletes frequently blame shortness of breath and poor performance on heat, when in fact it is due to elevated particle and ozone pollution.
• Avoid congested roadways. This is especially important for runners, who often train alongside busy roadways where combustion pollutants are worst. Pollution levels decline significantly just a few hundreds meters from a busy roadway, so opt for trails and local paths away from all the traffic.
• Give your lungs a break. Train indoors when possible, and train in a room with a high-performance air purifier whenever possible. IQAir air purifiers were used by the U.S. athletes for both living quarters and indoor training areas during the Beijing Olympics. A high-performance air purifier in your training room or home can make a difference for your overall health too.

Health experts agree that exercise is generally good for your health. But air pollution can turn a good thing into a bad one, especially when you train outdoors. By taking a few steps such as those above, you can improve athletic performance and protect your health for years to come.