The modified Bruce protocol (Exercise sessions).

<div><p>During the coronavirus disease 2019 pandemic, Filtering Facepiece Respirators (FFRs) were highly effective, but concerns arose regarding their physiological effects across different age groups. This study evaluated these effects based on age and exercise intensity in 28 participants (children, young adults, and older individuals). Physiological parameters such as respiratory frequency (Rf), minute ventilation (VE), carbon dioxide production (VCO<sub>2</sub>), oxygen consumption (VO<sub>2</sub>), heart rate (HR), metabolic equivalents (METs), percutaneous oxygen saturation (SpO<sub>2</sub>) and the concentration of O<sub>2</sub> and CO<sub>2</sub> in the FFRs were measured during treadmill tests with and without FFRs (cup-shaped, flat-folded, and with an exhalation valve). There was no significant difference in physiological effects between the control and FFR types, although Rf, VE, VCO<sub>2</sub>, VO<sub>2</sub>, METs, and HR increased with increasing exercise intensity. Depending on the exercise intensity, the O<sub>2</sub> level in the FFR dead space decreased, and the CO<sub>2</sub> level increased but this was independent of the dead space volume or FFR type. The study concluded that FFRs did not substantially impact daily life or short-term exercise, supporting their safe and effective use as a public health measure during pandemics and informing inclusive guidelines and policies.</p></div>