Respiratory muscle endurance training in cystic fibrosis

Background Respiratory muscle endurance training (RMET) has been shown to increase endurance performance in trained and untrained healthy subjects and patients with chronic obstructive pulmonary disease COPD). Two studies have been performed in adult patients with cystic fibrosis (CF), however with conflicting study design and results. Aims The aim of the study is to investigate the effects of an eight week RMET with the SpiroTiger ® device in children and adolescents with CF on respiratory endurance (RE), exercise endurance (EE), quality of life (QoL), lung function and clinical score. Methods 16 children (8-18 years, FEV 1 87.0 ± 25.8%pred [mean ± SD]) were included. All children underwent an incremental exercise test and a first RMET using the SpiroTiger ® device. Three weeks later patients were randomly assigned either group A or B. Group A performed eight weeks RMET followed by eight weeks standard chest physiotherapy whereas group B absolved the program in reverse order. Primary outcome measures consisted in a respiratory endurance test using the SpiroTiger ® device, a constant workload cycling test and CFQ, and secondary outcomes were clinical score and lung function. Results Respiratory endurance increased significantly from 3.7 ± 2.1to 16.8± 10.2 min (mean± SD); p < 0.001), whereas exercise endurance increased from 7.9 [8.1] to 10.25.8] min (median [IQR]; p= 0.008), respectively. All other outcomes including CFQ scores, clinical score, FEV1 (L) and FVC (L) did not change significantly after RMET. Conclusions The RMET leads to a significant increase in respiratory endurance and exercise endurance. However, other clinical relevant outcomes such as lung function, quality of life and clinical score were unaffected by RMET.