PT - JOURNAL ARTICLE AU - Mallet, Maria Christina AU - Hitzler, Michael AU - LurĂ , Marco AU - Kuehni, Claudia E AU - Regamey, Nicolas TI - Facemasks do not lead to abnormal gas exchange during treadmill exercise testing in children AID - 10.1183/23120541.00613-2021 DP - 2021 Jan 01 TA - ERJ Open Research PG - 00613-2021 4099 - http://openres.ersjournals.com/content/early/2021/12/02/23120541.00613-2021.short 4100 - http://openres.ersjournals.com/content/early/2021/12/02/23120541.00613-2021.full