Explain why air quality in the mountains can impact athletes' performance at high altitudes.

Composition of air and oxygen availability at altitude

As you ascend to higher altitudes, the air becomes thinner: less concentrated, less dense, but still composed of 21% oxygen. So, even though the percentage doesn't change, as atmospheric pressure decreases, you will breathe in significantly fewer oxygen molecules with each breath. This reduces what is called the partial pressure of oxygen, meaning the actual amount of oxygen available for your body. As a result, the body has to work twice as hard at altitude to obtain oxygen. The heart rate increases, breathing becomes deeper, the legs feel heavier, and naturally, performance can take a hit.

Impact of air pollutants on the respiratory function of athletes

Air pollutants such as ozone, nitrogen dioxide, and carbon monoxide quickly irritate the respiratory tract when breathing intensifies, for example during physical exertion at high altitude. These substances can trigger inflammation or contraction of the bronchi, thereby reducing airflow to the lungs. As a result, the athlete experiences shortness of breath, may feel a sensation of suffocation, and their recovery after exertion becomes slower. If exposure is prolonged or regular, these effects intensify: lung capacity gradually decreases, ultimately reducing the athlete's overall performance. It then becomes more challenging to maintain their pace, especially when the body is already struggling to cope with the altitude.

Effects of allergens and fine particles on physical performance

Breathing air laden with allergens (pollen, spores, etc.) or fine particles clearly reduces a sports person's respiratory capacity. These particles irritate the airways, causing inflammation and constriction, forcing the athlete to exert more effort to breathe normally. The result: a feeling of chest tightness, shortness of breath, decreased performance, and premature fatigue. Even in athletes without known allergies, prolonged exposure can induce a new respiratory sensitivity, seriously complicating training or competitions at altitude.

Physiological adaptation of athletes to poor air quality

The bodies of athletes can gradually adapt to poor air quality at high altitudes. Confronted with pollutants or reduced oxygen levels, their bodies trigger different mechanisms. First, at the respiratory level: faster and deeper breathing to capture as much oxygen as possible. Next, the body increases the number of red blood cells to enhance the ability to transport oxygen to muscles and organs. This response is called polycythemia. Through training in these less-than-ideal conditions, an athlete also improves their lung capacity, allowing for better filtration of irritating particles. However, it should be noted that even though these adaptations seem beneficial, they can have limits: prolonged exposure to heavily polluted air or high levels of allergens can still harm performance in the long run.