Exercise-inducible laryngeal obstruction (EILO) has been recognized as a not rare respiratory problem in youth practicing sports. The aim of the study was to test the mechanosensitivity of the larynx, and to identify the factors affecting it in a group of youth with proven EILO. Laryngeal sensory testing was performed in 54 adolescents and young adults with EILO. Laryngeal mucosal alterations were assessed according to the Reflux Finding Score (RFS). The data concerning diseases possibly affecting the upper airway, findings of previously performed flexible videolaryngoscopy during exercise, and RFS score were compared between the participants with laryngeal hyposensitivity and those with normal sensitivity. The participants with isolated vocal folds’ adduction during an EILO attack were compared with those who demonstrated supraglottis collapse. Testing revealed an increased threshold for mechanical stimuli in 81.5% of participants. Among participants with hyposensitivity, there were significantly more participants with dysphagia during EILO attacks than among the participants with normal laryngeal sensitivity. The hyposensitivity group had a significantly higher RFS score compared with the other group. Isolated vocal folds’ approximation was only observed in 11.9% of participants. These participants were younger and had asthma more frequently compared with the others. Only 16.9% of participants with EILO did not state symptoms related to gastroesophageal reflux. The decreased mechanosensitivity was detected in the majority of participants, suggesting that laryngopharyngeal reflux can be an important etiological factor. The problem of breathing difficulties during sport activities in youth can also be associated with the disproportionate growth of the respiratory tract.