Recently, the treatment of Cystic Fibrosis (CF) incorporated new modulators/enhancers of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). It is thus increasingly important to study the side effects of these drugs, their extrapulmonary effects and possible interaction with other drugs and with exercise. For this purpose, a randomized controlled trial is proposed to determine the effects of a telematic exercise intervention on muscle health, in a group of 48 children and adolescents with CF treated with these new generation CFTR modulators. They will be randomly assigned to two groups (exercise and control group). The effect of the intervention will be analysed measuring the variables of muscle health, cardiorespiratory fitness, lung function, body composition, inflammatory biomarkers and miRNAs. After completion of the intervention program, adherence to exercise and clinical evolution after one year will be analysed.