According to a study in Respirology, supplemental oxygen during exercise can improve pulmonary fibrosis patients’ breathing and workout capabilities, Pulmonary Fibrosis News reports.

Whether supplemental oxygen should be used during exercise is controversial, Pulmonary Fibrosis News reports, and conflicting studies have pointed out benefits and dangers of additional O2 during exercise.

Researchers conducted a clinical trial of 11 IPF patients who were randomly selected for supplemental O2 or compressed air. Participants exercised for one hour and results of patients’ blood levels of inflammatory proteins, oxidative stress, and muscle-metabolism compounds were analyzed, Pulmonary Fibrosis News reports.

While no change was detected at rest, researchers found that supplemental O2 “improved patients’ ability to exercise, prevented them from experiencing an oxygen shortage during workouts, and reduced their exercise-related breathing difficulties, a condition known as dyspnea,” Pulmonary Fibrosis News reports.

“We found that oxygen improved exercise performance, strengthening previous findings, and we provided the first evidence that oxygen effectively reduces exertional dyspnea in IPF,” the team wrote. “Supplemental oxygen may facilitate improved skeletal muscle metabolism through increased oxygen delivery. Supplemental oxygen may therefore be a beneficial adjunct to exercise training in IPF, optimizing physiological improvements through increased endurance training time.”