Exercise-induced bronchoconstriction (EIB) is a dysfunction of the respiratory tract consisting of transient airflow obstruction. This study is a retrospective analysis of two prospective studies concerning EIB symptoms in two adolescent populations. Our study group included 400 non-athletes and 101 athletes. Due to the similarity of indoor exercise conditions, an analysis was performed on the basis of where training took place. The study aims to assess the EIB prevalence in the following groups of adolescent children: non-athletes and athletes. In “indoor” athletes, the EIB prevalence was 22.4%. Among non-athletes, EIB was diagnosed in 10.2% (p= 0.007). A history of asthma was found in 6.5% of non-athletes and 29.3% of indoor athletes (p< 0.001). The incidence of EIB without asthma was higher in indoor athletes (14.6%) than in non-athletes (9.9%). Athletes achieved higher mean values in forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), and maximum expiratory flow rate at 25% (MEF25) parameters. In the group of non-athletes, higher results were observed in forced expiratory volume in one second % of vital capacity (FEV1%VC), MEF50, and MEF75. The findings of the study present the complexity of the EIB diagnosis among children training in an indoor environment.