For days a note published in La Vanguardia entitled “WHO recommends not using a mask during intense physical activity.”
Since he has had 1,361 Facebook interactions in the last seven days according to Crowd Tangle, which measures how viral the content published on social networks is, we decided to pass the Lie Detector to him and found that it is true, but the explanations it gives are misleading.
On December 1, WHO updated its mask use guide to protect against covid.
In the section of “Questions and answers about Covid-19 and masks“It says” Even when you are in an area of COVID-19 transmission, masks (face masks) should not be worn during vigorous physical activity due to the risk of reducing your breathing capacity. ”
Thus, as the headline of La Vanguardia says, the WHO does not recommend the use of masks during intense physical activity.
But the media begins its note saying that the WHO “Ensures that oxygen availability decreases and increases the levels of CO2 we absorb, thus reducing the ability to breathe comfortably.”, When this is not what the entity says.
There is no evidence that wearing a mask reduces the oxygen we breathe or increases CO2 levels
In the section of Mythbusters (Mythbusters) from the WHO website says that prolonged use of the mask does not increase CO2 levels or reduce the oxygen we breathe.
As we have already checked, there is no scientific evidence that shows that the use of masks generates hypoxia, which is the lack of oxygen in the blood, cells and tissues that can affect the brain.
With masks there is no lack of oxygen because they allow you to inhale and exhale at the same time, so they do not interrupt the breathing process.
“No, the use of masks does not produce hypoxia,” said María Elisa Calle, an expert in epidemiology and public health, the factchecking portal Damn. Masks, as he explains, are not something that stalls the breath: air enters through the sides and the top.
About carbon dioxide (CO2) is known from hypercapnia, the increase of this gas in the blood. This syndrome can be caused by respiratory diseases, increased physical effort or a reduction in oxygen levels in the air, among other factors.
But the increased inhalation of CO2 with a mask is not significant enough to cause respiratory problems. “The mask lets air in and out and all the masks used are naturally permeable to air,” explained Tiago Alfaro, vice president of the Portuguese Society of Pneumonology, to the factchecking portal Polygraph.
“In a mask that is permeable, however, there may be a small amount of air that actually remains in front of the mouth, behind the mask. [tapabocas], and that amount of air ends up being inhaled and exhaled. But it is such a small amount that it does not make any difference, “said Alfaro.
Daniel Pahua, Professor of Public Health at the Autonomous University of Mexico (UNAM), explicó a AFP that the use of the mask by itself does not lead to hypercapnia, “unless the patient has a functional problem, but then it would not be due to the use of face masks.”
A scientific literature review on face masks and exercise, published in November in the Annals of the American Thoracic Society and led by Susan Hopkins, found that no significant effects of face masks have been found on the cardiorespiratory system in processes related to the exchange of oxygen and CO2 or in the functioning of the lungs.
They clarified that the scientific evidence is constantly evolving, so further research on the subject is still necessary.
Wearing a mask and exercising can be uncomfortable
Despite this, wearing a mask during intense exercise can make you feel more short of breath and short of breath, known as dyspnea.
According to the Hopkins-led review, this can be uncomfortable.
In a corroboration of factual AFP, they asked several experts if the use of masks can produce the sensation of suffocation. They all agreed that it was, but “it doesn’t mean real suffocation.”
Jorge Gómez, a surgeon specializing in sports medicine, agrees that being in a mask can generate a certain degree of dyspnea or asphyxia, “but that does not have to affect the physiological state of lung capacity and ventilation.”
He states that dyspnea is a subjective sensation of each person when they feel that they cannot take air or that the air is not enough for exercise.
Luis Jorge Hernández, a doctor in public health, told La Silla that masks can cause discomfort, but not because the person breathes less oxygen and more CO2.
For all the above, the headline of La Vanguardia is true, but the reasons it gives as justification are not true and the WHO told us. That is why we classify this note as misleading.