The Filtering Facepiece Respirator Increases Inspiratory Time, But Does Not Change the Involvement of Breathing Compartments

The study involved 21 students majoring in physical education and sports. All subjects were physically active, engaging in approximately 260 minutes of physical activity per week, and they possessed a high level of fitness. Inclusion criteria required participants to be free from injury, capable of providing written consent, and within the age range of 19 to 26 years. Exclusion criteria included individuals who smoked or had chronic pulmonary or cardiac diseases. This research received approval from the Ethics Committee at the Faculty of Education, University of South Bohemia, Reference Number: 002/2018. All procedures conducted within the study adhered to the ethical standards outlined by the Institutional Research Committee and the principles of the Helsinki Declaration.

Protocol:

Participants were instructed to visit the laboratory on two occasions to complete two separate tests during each session, specifically the Opto-electronic plethysmography (OEP) test during resting in a standing position and the OEP test during a Graded Exercise Test (GXT). The time interval between the testing days was three days. Participants were randomly assigned to two groups using randomizer.org. The first group performed three tests while wearing a Face-Fit Respirator (FFR), while the second group performed the tests without the mask. During the second visit, participants switched to the opposite condition. The N95 respirator was employed in this study as the gold standard for protection against aerosol transmission, particularly during the COVID-19 pandemic. A new mask was used for each test. In the Standing Test (STD), participants were instructed to maintain a stationary standing position and engage in spontaneous, quiet breathing without speaking or altering their posture while OEP data was collected. The first two minutes were designated as an adaptation period, followed by data collection for an additional three minutes. In the context of the Graded Exercise Test (GXT), OEP data was collected during the final minute of each three-minute stage.

Opto-Electronic Plethysmography:

The analysis of breathing patterns and volumes of chest wall compartments was conducted using opto-electronic plethysmography (BTS Bioengineering, Milan, Italy). This device comprises eight cameras, with five positioned anteriorly and three posteriorly relative to the participant. Additionally, 89 reflective markers were affixed to the participant's chest, abdomen, and back to track movements of the trunk. This technique has previously demonstrated validity in both resting and maximal exercise conditions.