Can we do sports in the city?

It's undeniable that playing sports is one of the keys to a healthy lifestyle.

Jogging in the heart of Paris, however, remains a very questionable practice.

While we know that breathing polluted outdoor air exposes us to risks, what happens if we combine air pollution and increased breathing?

At R-PUR, we are convinced that a global understanding of air pollution would make it possible to change mentalities more quickly.

We have therefore deciphered for you, athletes, the effects of this practice, and the actions to adopt.

How do we determine air pollution?

Atmospheric pollution is observed through four key indices: the presence of sulfur dioxide,nitrogen dioxide , ozone, then PM10 .

This is the Atmo index, which since January 1, 2021, has also included PM 2.5, these fine particles smaller than 2.5 micrometers :

There are regulations for each of these sources of pollution, and thresholds to be respected based on WHO recommendations.

When one of the thresholds exceeds the recommendations of the WHO, a pollution peak is declared.

And it is especially during these pollution peaks that the practice of outdoor sport becomes highly inadvisable.

Why pollution represents a greater danger for athletes?

First of all, it is important to remember that exposure to air pollution can cause health problems even without physical activity. The elderly, pregnant women, young children, are the most fragile.

But when you combine sport and pollution, you increase these risks. And this for the whole population.

This risk is explained by the fact that, during a sporting activity, you generally inhale more air and breathe it deeper into your lungs.

And because you're more likely to breathe deeply through your mouth during exercise, the air you inhale usually bypasses the natural filter in your nasal passages.

We can always ask ourselves: do the benefits of sport outweigh the effects of pollution?

The answer is yes, according to a study conducted by the European Society of Cardiology .

What are the health effects?

The study conducted by the European Society of Cardiology took place in South Korea, on a sample of 1.5 million people and over a period of 5 years.

The latter analyzes the exposure to fine particles PM2.5 and PM10 of the participants of this study, all aged between 20 and 39 years.

We compare the exposure to PM2.5 and PM10 of participants doing sports (given in MET-min, which is the metabolic equivalent Metabolic Equivalent of Task , MET ) to their Hazard Ratio, which corresponds to the risk of contracting a cardiovascular disease .
The result of this study is as follows: playing sports is beneficial for health. It even reduces the risk of contracting cardiovascular disease by 40%.
On the other hand, playing sports in a polluted environment (ie beyond the WHO recommendation threshold) will increase this same risk by 30%.
As an indication, in Paris in the first quarter of 2021, this threshold was exceeded 42 days out of 90, i.e. one day out of two.
It is therefore scientifically proven: playing sports increases the risk of cardiovascular disease.
As a reminder, cardiovascular disease (CVD) is the leading cause of death worldwide. The Global Burden of Disease reports 17 million deaths attributed to CVD between 2006 and 2016.
How to limit this damage while continuing to exercise?

Playing sports in the city: the user manual.

In order to make the most of the benefits of sport, here is an exhaustive list of actions to adopt.

1. Avoid pollution peak alerts.

To limit the damage of pollution as much as possible, the first thing to do is to limit your exposure.

For this, you can first get information via Approved Air Quality Monitoring Associations like Airparif for Île-de-France.

Ile-de-France residents can therefore visit the AirParif website to obtain air quality forecasts in Paris and potential pollution peaks.

Paris is not the only city whose cases of pollution are referenced: each region depends on a particular organization.

For example, if you live in the Bordeaux region, Atmo Nouvelle-Aquitaine will be your reference association.

2. Watch the weather

The weather and weather outside significantly affects air quality.

Thus, relying on weather phenomena can also be a good starting point if you know the movements of the weather:

- The sun and hot weather is not an ally for athletes because it promotes certain pollutants, such as Ozone.

The reactions that create harmful ozone in our atmosphere require sunlight. In summer, and especially during extreme heat waves, ozone often reaches dangerous levels in cities, especially near major highways.

- When it is cold, we more distinctly perceive the smell of exhaust pipes and chimneys. Does this mean that this pollution is more present, or just more visible?

The answer to this question is a bit of both. By a phenomenon of temperature inversion, the pollution will find itself "blocked" on the surface and will be more difficult to disperse.

The cold therefore promotes air pollution. If you want to deal with the subject in more depth, the Atmo organization deciphers the phenomena of temperature inversion in this article .

- Rain , on the other hand, can have a positive and cleansing effect on air quality.

To limit your exposure to pollutants, exercise outdoors just after heavy rains, when particle concentrations are lower.

- The wind, on the other hand, is a double-edged sword. Winds can sweep pollutants out of an area and lower their concentrations, rapidly improving air quality.

On the other hand, they can transport pollutants away from their sources, and lift dust to the ground, which impoverishes the quality of the air.

3. Favor less intense physical activities.

In general, we take about 15 breaths per minute during normal activities. During physical activity, you can reach up to 100 breaths per minute.

More breaths introduce more pollutants into your airways.

This is why, outdoors, less intense activities are rather recommended. For example, you can swap running for walking.

Anticipating the different episodes of pollution, relying on the weather, training in a gym, or even radically changing your physical activity, are thus advice that you can apply if you want to protect yourself from pollution damage.

At R-PUR, we are convinced that there are less restrictive solutions.

What about anti-pollution masks?

During the Beijing International Marathon on October 19, 2014, the concentration of PM 2.5 exceeded 300ug/m3. The city of Beijing then issued an "orange alert" to air quality due to a case of heavy pollution.

Therefore, many marathon runners have decided to wear protective masks in order to protect themselves from pollution levels.

When choosing an anti-pollution mask for physical activity, three essential parameters must be taken into account:

Efficiency : what pollutants will my mask filter, and up to what size?

Hermeticity: in other words, will the outside air enter my mask?

Comfort: will I be able to breathe well in my mask?

At R-PUR, we have therefore developed a solution that perfectly meets these three criteria :

We filter particles with a size of 50 nanometers (PM0.05) is 50 times smaller than PM2.5, so the efficiency is there.

In terms of hermeticity, depending on the morphology of your face, we will filter between 99.86% to 99.98% outside air.

Finally, our hot air extraction valve allows the flow of hot air to be evacuated 60 times faster than a conventional valve, even when cycling or running.