Effects of Exercise on Respiratory Flow and Sputum Properties in Patients With Cystic Fibrosis.

The article compares ventilation, respiratory flow and sputum properties following treadmill and cycle exercise with resting breathing or control to determine the physiologic mechanisms by which exercise may clear secretions in cystic fibrosis (CF) patients. Fourteen adult subjects with CF underwent 20 minutes of resting breathing, treadmill and cycle exercise in a three-day crossover study. Ease of expectoration and reductions in sputum mechanical impedance were found to be experienced by the subjects following exercise.