The effect of respiratory muscle training on children and adolescents with cystic fibrosis: a systematic review and meta-analysis.

This review pulled together six controlled trials, involving 151 children and adolescents with cystic fibrosis in total, to look at whether respiratory muscle training helps this group. Respiratory muscle training involves exercises designed to strengthen the muscles used for breathing, either the ones you use to breathe in (inspiratory) or breathe out (expiratory). The researchers wanted to know if this kind of training improved muscle strength, endurance, lung function, cough, exercise capacity, and quality of life, compared to a sham treatment or no treatment at all. When they combined the data across studies, there was no measurable difference between the training and control groups for respiratory muscle strength, lung function, or exercise capacity.

However, when they looked specifically at inspiratory muscle training on its own, a subgroup analysis suggested it might help increase the maximum pressure someone can generate when breathing in. A more qualitative look at the data (since not everything could be statistically pooled) also hinted that training might help respiratory muscle endurance, and no adverse effects were reported. The authors are careful to note that the studies varied a lot in quality and methods, and two of the six were only published as abstracts, meaning less detail was available to judge them. Overall, they describe the evidence for benefit as low certainty, and say more, better-quality research is needed before firmer conclusions can be drawn.

This review looked at whether breathing muscle exercises, sometimes called respiratory muscle training, make a difference for children and teenagers with cystic fibrosis. Researchers combined results from six small studies involving 151 young people in total, comparing those who did the training to those who had a sham version or no training. When all the results were combined, there wasn't a clear overall difference in breathing muscle strength, lung function, or exercise capacity between the groups.

That said, when researchers looked more closely at one specific type of training, the kind focused on strengthening the muscles used to breathe in, there were signs it might help increase how much pressure those muscles could generate. There were also some hints, though less certain, that this kind of training could help with breathing muscle endurance, meaning how long the muscles can keep working before tiring. Importantly, no harmful side effects were reported in any of the studies.

The researchers are honest that the overall quality of evidence is still low, partly because the studies were quite different from each other and some had limited published detail. This means the picture is still incomplete, and more well-designed research is needed to understand who might benefit and how.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

This systematic review and meta-analysis synthesised six controlled trials (four parallel, two cross-over) totalling 151 paediatric and adolescent cystic fibrosis patients, examining respiratory muscle training against sham or no intervention. Pooled analyses found no significant difference in respiratory muscle strength, lung function, or exercise capacity between groups.

A subgroup analysis specifically isolating inspiratory muscle training suggested a benefit for maximal inspiratory pressure, and qualitative synthesis (where pooling wasn't feasible) indicated a possible benefit for respiratory muscle endurance, with no adverse events reported across the included trials. The authors flag considerable heterogeneity in methodology and study quality across the six trials, assessed using the Cochrane Risk of Bias Tool 2. Two of the six studies were only available in abstract form, restricting the depth of methodological appraisal possible.

Using GRADE, the certainty of evidence supporting any benefit was rated low. The authors' interpretation is that although current evidence doesn't confidently support broad claims of effectiveness, the signal for inspiratory muscle training on inspiratory pressure and the endurance findings are clinically plausible enough to warrant better-designed trials. This review does not establish respiratory muscle training as an effective intervention across the board, but it also doesn't rule out benefit in specific outcomes, particularly inspiratory strength and endurance, pending stronger evidence.