Results: Distance was not modified by the mask (P=0.99). Dyspnea variation was significantly higher with surgical mask (+5.6 vs. +4.6; P<0.001) and the difference was clinically relevant. No difference was found for the variation of other parameters. Conclusion: Wearing a surgical mask modifies significantly and clinically dyspnea without influencing walked distance. https://pubmed.ncbi.nlm.nih.gov/29395560/