Strength vs aerobic training in children with cystic fibrosis: a randomized controlled trial.

STUDY OBJECTIVE Exercise has the potential to improve the ability of a patient with cystic fibrosis (CF) to cope with the physical demands of everyday life, and may improve prognosis. The purpose of this study was to compare the effects of a home-based, semi-supervised, upper-body strength-training regimen with a similarly structured aerobic training regimen. DESIGN Data were collected during a 1-year randomized clinical trial. SETTING Counselors conducted in-home visits with the participants once per week for the first 8 weeks followed by monthly visits for the remainder of the study. PATIENTS Sixty-seven patients with CF, aged 8 to 18 years, participated in the trial. INTERVENTION Participants in both exercise conditions were encouraged to exercise at least three times per week for 1 year. Each child in the aerobic group was given a stair-stepping machine, and each child in the upper-body strength training group was given an upper-body-only weight-resistance machine. MEASURES AND RESULTS Aerobic fitness, pulmonary function, quality of life, and strength were measured at baseline, at 6 months, and at 12 months. Strength training increased the maximum weight lifted for biceps curls significantly more than aerobic training (p < 0.02). However, this differential did not remain significant after control for increase in height. Both training procedures were associated with increased strength (p < 0.002) and physical work capacity (PWC) [p < 0.033]. CONCLUSIONS We concluded that strength and aerobic training may increase upper-body strength, and that both types of training may increase PWC for children with CF. Future trials should be conducted with no-training control subjects and larger samples to increase statistical power.