Is exercise and electrostimulation effective in improving muscle strength and cardiorespiratory fitness in children with cystic fibrosis and mild-to-moderate pulmonary impairment?: Randomized controlled trial.

Children with cystic fibrosis often lose muscle strength and fitness alongside their lung problems, and physiotherapists have wondered whether resistance training, perhaps boosted by electrical muscle stimulation, could help. This randomized trial compared a supervised 8-week resistance-training program, with or without added neuromuscular electrical stimulation, against usual care in children and teenagers with mild-to-moderate lung impairment from cystic fibrosis. Both exercise groups showed better functional capacity and notably greater gains in muscle strength across several muscle groups, including the thighs, chest, back, and grip, compared with the control group. Adding electrical stimulation did not produce any extra benefit beyond exercise alone, and none of the groups showed significant improvement in cardiorespiratory fitness, lung function, or quality of life.

The trial was small, with only 27 patients analysed across three groups, so these findings should be seen as an early signal rather than definitive proof of broad clinical benefit.

If your child has cystic fibrosis, you may already know that keeping muscles strong is part of managing the condition alongside breathing treatments. This study looked at whether an eight-week structured strength-training program, done three times a week, could help children and teenagers with mild-to-moderate lung problems from cystic fibrosis, and whether adding a device that stimulates muscles with small electrical pulses made things even better. The children who did the exercise program, with or without the added electrical stimulation, got noticeably stronger in their legs, chest, back, and grip, and did better on a physical function test than those who just followed standard care.

However, the researchers did not see improvements in overall fitness during exercise testing, lung function, or reported quality of life. The electrical stimulation add-on gave no extra advantage over exercise alone. This was a small study, so while the strength gains are encouraging within this trial, this evidence alone is not enough to draw broad conclusions about the long-term or wider health benefits of the program.

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

This randomized controlled trial allocated 27 children and adolescents with cystic fibrosis and mild-to-moderate pulmonary impairment to control, exercise, or exercise plus neuromuscular electrical stimulation (NMES) groups, over an 8-week supervised program (3 sessions weekly, 60 minutes each). Muscle strength outcomes showed statistically significant between-group differences favoring both exercise arms over control, with large effect sizes for quadriceps (p=0.004, η²p=0.401), pectoral (p=0.001, η²p=0.487), dorsal (p=0.009, η²p=0.333), and handgrip strength (p=0.028, η²p=0.278).

Functional capacity also differed significantly in favor of both exercise groups. No significant interaction effects were found for cardiorespiratory fitness, lung function, or quality of life, indicating these outcomes did not improve differentially with training in this sample. Critically, NMES added to exercise produced no additional benefit over exercise alone on any measured outcome, suggesting the strength and functional gains were driven by the resistance training itself rather than the stimulation component. The small sample size, split across three arms, limits statistical power and generalizability, and the abstract does not report between-group comparisons for the two exercise arms against each other beyond both outperforming control.

These findings support resistance training as a strength-building adjunct in this population but do not establish effects on aerobic fitness, respiratory outcomes, or quality of life.