Medical research suggests, and this is known from practice, that cystic fibrosis patients have elevated breathing rates and increased tidal volume at rest, and these differences in breathing are even more noticable duirng exercise. In simple terms, they breathe much more than the medical norm and have heavy breathing during exercise. Overbreathing or hyperventilation leads to oxygen deficiency on body cells and hundreds of other abnormal effects, including problems in various body organs which are aggravated by the presence of the faulty CFTR gene.