"All of these positive changes in lung mechanics allowed the patients to markedly improve exercise endurance time," they note.
And finally, "it is likely that the exercise protocol used, capable of inducing high levels of ventilation relative to subject's maximal ventilation for a prolonged period of time, has amplified the effect of heliox breathing in reducing turbulent airway resistances," the authors say. In a related observation, they believe that "the high-intensity constant work rate test utilized allowed us to clearly detect the beneficial effect of small changes in lung mechanics induced by heliox breathing on exercise capacity."
The authors conclude that "heliox breathing, by reducing airflow limitations, lung dynamic hyperinflation and dyspnea sensation, is capable of improving high-intensity exercise endurance capacity in moderate to severe COPD patients." However, they note that "further studies are needed to verify the potential role of heliox supplementation during exercise rehabilitation programs in COPD patients."