The present update is dedicated to the evolution of the interaction between heart failure (HF) and exercise and how the scientific community has handled it. Indeed, on the one hand, HF is a leading cause of morbidity and mortality with a stable prevalence from 1998 onward varying between 6.3% and 13.3%. On the other hand, exercise is seen as a diagnostic and prognostic tool as well as a therapeutic intervention in chronic HF. More precisely, the knowledge, the clinical application, and the research interest on the mutual interactions between exercise and HF have different phases in disease progression:

• Before HF onset (past): exercise provides protective benefit in preventing HF (primary prevention).
• With HF present: exercise improvement with training provides benefits in HF (secondary prevention).
• The prediction of future in HF patients: exercise impairment, as a leading characteristic of HF, is used as a prognostic factor.