While exercise therapy for heart failure (HF) patients with low heart function has been shown to be an effective prognostic tool, the level and format of exercise that yields optimal effects is still unclear. In a study to understand how exercise-induced oxidative stress affects patients with HF, researchers from the Osaka City University (OCU) Graduate School of Medicine have shown that patients who underwent a cardiopulmonary exercise test and showed an increased in oxidative stress had a poor prognosis. Their findings were published in the European heart journal: ESC Heart Failure.