Hospitalization and treatment for cardiovascular disease is one of the main contributors to disability in older adults. Moderate intensity continuous aerobic and resistance training have been the cornerstone of cardiac rehabilitation (CR) for decades to remediate hospital-acquired functional deficits, but some groups receive less or minimal functional benefit from this training. The proposed studies seek to optimize recovery of aerobic fitness and physical function among older cardiac patients using a novel high intensity training regimen with the long-term goal of reducing subsequent disability and improving clinical outcomes.