Continuous laryngoscopy was performed during the CPET using a transnasal flexible video-laryngoscopy (ENF TYPE V2, video processor CV-170; OLYMPUS, Tokyo, Japan) as described previously [31 (link)]. Laryngeal obstruction during treadmill running was assessed and rated according to a modified version of the classification described by Maatet al. (Figure 1) [13 (link)]. Laryngeal obstruction on either glottic or supraglottic level at moderate and maximum exercise was rated from 0 to 3 at each level, giving a score ranging from 0 to 12 (CLE score). CLE test recordings were evaluated blinded in retrospect by two experienced reviewers (O.D. Røksund and H.H. Clemm), and disagreements were resolved by consensus.