Fig. 6From: The Impact of Ubiquitous Face Masks and Filtering Face Piece Application During Rest, Work and Exercise on Gas Exchange, Pulmonary Function and Physical Performance: A Systematic Review with Meta-analysisRisk of bias rating for each item, displayed as traffic light plots (above) and as summary bar plots (below). The colours indicate high (red), unclear (yellow) or low (green) risk for the respective bias domain/itemBack to article page