It's not too late to exercise after a heart attack. After the heart attack, the patient can receive therapy such as device (pacemaker, implantable cardioverter-defibrillator or cardiac resynchronization therapy) and drugs (beta blocker, statin, ACE inhibitor). They are also advised to have some moderate exercise regularly to increase their exercise capacity. There is also heart disease due to exercising too much as seen in hypertrophy cardiomyopathy