Effects of a remotely supervised resistance training program on muscle strength and body composition in adults with cystic fibrosis: Randomized controlled trial.

INTRODUCTION: Among the limited studies on physical exercise interventions in adults with cystic fibrosis (CF), few have specifically addressed the improvement of peripheral muscle strength and body fat-free mass. The aim of this study was to examine the impacts of a remotely supervised, individualized 8-week resistance training program of moderate to high intensity on strength and body composition in these subjects. METHODS: This was a randomized controlled trial performed in adults with CF. The exercise group (EX) performed three 1-h resistance training sessions per week over 8 weeks. The control group (CON) followed the physical activity recommendations of their physician. The main outcomes were muscle strength and body composition, with secondary measures including pulmonary function and quality of life. Two-way repeated measures analysis was used. RESULTS: In 23 participants (age 32.13 ± 7.72 years), the intervention showed a significant beneficial effect on leg press strength, with a large effect size, both in absolute (p = 0.011; η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ = 0.281) and relative (p = 0.007; η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ = 0.310) terms. Large intervention effects were observed on total fat mass (p < 0.001; η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ = 0.415), body adiposity index (p < 0.001; η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ = 0.436), and fat mass index (p < 0.001; η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ = 0.445), all showing reduction in the EX group. In addition, significant large size effects were detected on total fat-free mass (p = 0.046; η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ = 0.177), trunk fat-free mass (p = 0.039; η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ = 0.188), and fat-free mass index (p = 0.048; η p 2 $$ {\eta}_{\mathrm{p}}^2 $$ = 0.174), all favoring exercise. No significant effects were observed on pulmonary function and quality of life. CONCLUSIONS: An 8-week remotely supervised resistance training program, with moderate to high intensity, effectively improved lower limb muscle strength and body composition.