Effects of inspiratory muscle training on physical fitness in cystic fibrosis: a systematic review and meta-analysis

Background: Cystic fibrosis (CF) is a multisystem disease primarily affecting the lungs. It impacts physical fitness due to increased bronchial secretions and exercise intolerance. Inspiratory muscle training (IMT) is recommended as a pulmonary rehabilitation approach. Therefore, we aimed to examine the effect of inspiratory muscle training on health-related physical fitness in CF. Methods: Articles were searched in five databases from inception to June 2025. All randomized controlled trials comparing IMT with a control group in individuals with cystic fibrosis were included. Four randomized controlled trials involving a total of 90 individuals with CF met the inclusion criteria. Results: A significant difference was found in the change in maximal work capacity, maximal minute ventilation, and exercise duration during the exercise test in the IMT group compared to the control group. However, no significant difference was observed in the change in maximal oxygen uptake, 6-minute walk test distance, and oxygen saturation during the 6-minute walk test between the IMT group and the control group. Conclusion: The therapeutic effectiveness of IMT for physical fitness is still uncertain. The evidence is not enough to assess how IMT can be used to enhance health-related physical fitness in CF. Further research should explore the optimal intensity and duration of IMT training needed to improve cardiorespiratory fitness. Additionally, future studies should evaluate how effective IMT is when examining its impact on health-related physical fitness.