Lung function and ventilatory response during high-intensity treadmill walking in adults with cerebral palsy: a cross-sectional study

OBJECTIVE: To investigate lung function and ventilatory response during cardiopulmonary exercise testing in adults with cerebral palsy and assess the relationship between perceived breathlessness and breathing reserve at maximal exertion. DESIGN: Prospective, cross-sectional study. Inclusion period October 2023-June 2024. SUBJECTS: Adults with spastic cerebral palsy, Gross Motor Function Classification Score (GMFCS) I-III (n = 100). METHODS: Spirometry and cardiopulmonary exercise testing were conducted. Ventilatory response during exercise was assessed via tidal volume and respiratory rate. Perceived breathlessness was compared with breathing reserve at maximal exertion. RESULTS: 89 participants completed all tests (GMFCS I = 62, GMFCS II = 20, GMFCS III = 7); 90% had lung function within normal limits. Age- and sex-adjusted maximal oxygen uptake was lowest in group III (p < 0.01). At maximal exertion, 70% had breathing reserve < 20%, indicating ventilatory limitation. Breathing reserve did not significantly differ between those who did and did not report breathlessness as the limiting factor at maximal exertion. Tidal volume and respiratory rate showed expected values at maximal exertion. CONCLUSION: Lung function was normal in most participants, yet ventilatory limitations were common during maximal exercise. Perceived breathlessness was not related to breathing reserve at maximal exertion.