Cycling can help strengthen the immune system and thus increase defenses against pathogens and various diseases. Despite the existing consensus, the complexity of the subject prevents an accurate understanding of this relationship. Other factors such as stress, sleep quality or nutrition also require special mention.

The benefits of cycling – and sport in general – are widely known. Much has been written about the positive consequences both on the physical fitness of the cyclist and on his or her mental well-being. However, we must also consider another point in favor of aerobic exercise -the family to which cycling belongs-: the immune system.

Thus, beyond forging well-defined quadriceps or having a de-stressed head, the cyclist strengthens the body’s immune system. And this improvement translates into a lower incidence of certain diseases or pathogens.

Before we begin, it is necessary to understand what the immune system is. The definition – taken from the Dictionary of the Royal National Academy of Medicine of Spain – explains that it is the “set of organs, cells and molecules” that “are responsible for distinguishing between the self and the other, as well as protecting the body against any foreign element.

In other words, the immune system is the defense we deploy to protect ourselves from infections and diseases in a fight against different pathogens and toxins, as explained by the Clínica Universidad de Navarra.

The immune system is a rather broad term that contains a rich array of defenses ranging from relatively simple processes to some that, due to their complexity, are still not known exactly.

Once the picture of the immune system has been drawn, it is easy to understand why it benefits from cycling or any other aerobic exercise. By increasing the heart rate, the circulation of white blood cells -involved in defense- is stimulated.

Speaking to Bike Radar, Dr. Campbell stated that “cells that have been resting somewhere in the body, in response to the increased heart rate, are pushed into the bloodstream to carry out the early stages of immune surveillance.”

These cells are then directed to different tissues as a check once the exercise is over. In the past, low levels of white blood cells in post-workout blood were interpreted as a sign that athletes might suffer more infections; now it is thought that they ‘go out’ of the blood to look for pathogens in other tissues.

Other voices suggest that this type of exercise generates an anti-inflammatory ecosystem that helps fight some diseases.

Perhaps it is too categorical to say that cyclists have a better immune system, although it does seem clear that immune health is better maintained over time.

Stress is another key player: the presence of stress in the body increases cortisol, which is detrimental to the immune system. Thus, reducing stress from cycling would help reduce the frequency of infections or certain diseases.

Exercising with inadequate nutrition could also increase cortisol levels; a circumstance that would occur with a low glycogen and carbohydrate state, according to expert Will Girling.

The relationship between nutrition, physical exertion and exercise is still unclear and there are several avenues of thought.

Despite the benefits of aerobic exercise, it is important to pay attention to the immune system. Thus, if you have a respiratory infection, you should leave the bike parked and reserve the pedals for two days after the symptoms have disappeared.

On the other hand, there are some general guidelines that reduce infections: proper hygiene -and prudent measures to avoid excessive contact with infected people-, less stress, adequate sleep quality and proper nutrition.

It is clear that cycling does not provide the cyclist with an insurmountable organism, although it does strengthen the lines of defense and allows a better response to the external attack of pathogens and diseases. Even so, the best option is to consult a doctor, who will be able to analyze our particular case and give an accurate diagnosis.