Obesity is associated with increased prevalence of cardiovascular (CV) disease (CVD) risk factors, which may adversely impact CV structure and function and may increase the prevalence of most CVD, particularly heart failure (HF) and coronary heart disease (CHD). Physical activity (PA), exercise training (ET) and cardiorespiratory fitness (CRF) are all associated with marked reductions in most CVD, including HF and CHD. Additionally, PA/ET and, especially CRF, markedly alter the relationship between adiposity and subsequent major CVD outcomes and dramatically impact the "obesity paradox," which are all reviewed, including attention to the debate regarding "fitness versus fatness" for long-term prognosis, including in patients with established CVD.