The study is conducted in the context of the COVID-19 pandemic in general, and more specifically in the context of the evaluation of the use of protective masks as a barrier to the spread of the virus. The wearing of masks is one of the recommended barrier measures to limit the spread of the SARS-CoV-2 virus responsible for COVID-19. It is recommended in all circumstances, and mandatory in some. Regardless of the type of mask used (noting that the so-called "surgical" masks are by far the most common), there are various disadvantages associated with wearing them. Dyspnoea (unpleasant or upsetting perception of respiratory activity) is one of these disadvantages. It can lead to reluctance to wear the mask, or to the adoption of inappropriate practices that reduce its effectiveness. This "side effect" of the mask is more pronounced in patients with underlying respiratory diseases. However, not all mask designs are equivalent in terms of their physical properties, which can theoretically generate varying levels of dyspnoea. It is therefore important to determine which mask designs are more or less dyspnogenic, in order to guide the preferential use of certain designs in certain patient categories. The TOLMASK study (Tolerance of SARS-CoV2 Surgical Masks in Patients with Chronic Respiratory Diseases) is a prospective, randomised, triple-blind, single-centre study comparing several surgical masks in a crossover design. The primary objective of the study is to evaluate the respiratory tolerance of different surgical masks and the secondary objective is to evaluate their general tolerance.

The study was conducted in the context of the COVID-19 pandemic in general, and more specifically in the context of the evaluation of the use of protective masks as a barrier to the spread of the virus. The wearing of masks is one of the recommended barrier measures to limit the spread of the SARS-CoV-2 virus responsible for COVID-19. It is recommended in all circumstances, and mandatory in some. Regardless of the type of mask used (noting that the so-called "surgical" masks are by far the most common), there are various disadvantages associated with wearing them. Dyspnoea (unpleasant or worrying perception of respiratory activity) is one of these disadvantages. It can lead to reluctance to wear the mask, or to the adoption of inappropriate practices that reduce its effectiveness. This "side effect" of the mask is more pronounced in patients with underlying respiratory diseases. However, not all mask designs are equivalent in terms of their physical properties, which can theoretically generate varying levels of dyspnoea. It is therefore important to determine which mask designs are more or less dyspnogenic, in order to guide the preferential use of certain designs in certain patient categories. The TOLMASK study (Tolerance of SARS-CoV2 Surgical Masks in Patients with Chronic Respiratory Diseases) is a prospective, randomised, triple-blind, single-centre study comparing several surgical masks in a crossover design. The primary objective of the study is to evaluate the respiratory tolerance of different surgical masks and the secondary objective is to evaluate their general tolerance.

The inclusion criteria are : 1) patient hospitalised in the respiratory and neuro-respiratory rehabilitation department of the R3S department at the Pitié-Salpêtrière Hospital (Pr Gonzalez-Bermejo); 2) patient enrolled in a respiratory rehabilitation process including exercise training on a cyclo-ergometer or treadmill; 3) hospitalisation in the respiratory rehabilitation department either post-exacerbation of COPD (usual recruitment of the department) or post-COVID (depending on the epidemic situation at the time of the study); 4) patient of age.

The criteria for non-inclusion are 1) Exercise re-training under mask ventilatory assistance; 2) Presence of a tracheotomy; 3) Psychiatric disorders (at the discretion of the referring physician); 4) Insufficient command of the French language; 5) Refusal to participate in the study.

50 patients will be included, over a period of 4 months. The duration of participation is 5 days.

Inclusion Criteria:

• Patient hospitalised in the respiratory and neuro-respiratory SSR service of the R3S department at the Pitié-Salpêtrière Hospital (Pr Gonzalez-Bermejo)
• Patient enrolled in a respiratory rehabilitation process including exercise training on a cyclo-ergometer or treadmill
• Hospitalization in respiratory rehabilitation unit either in post-exacerbation of COPD
• age over 18

Exclusion Criteria:

• Exercise training under mask ventilation support
• Presence of a tracheostomy
• Psychiatric disorders (at the discretion of the referring physician)
• Insufficient command of the French language
• Refusal to participate in the study

not everyone involved in the research (patients, investigators, caregivers, and statistical analysis stakeholders) will know which mask the patient is using at which time.