Beware of high-intensity workouts as they can be fatal

Death on the treadmill

Dr Akshay Mehta, interventional cardiologist

 Afew years ago, Nikhil Gupta (name changed), a young man in his thirties, did his regular workout on the treadmill at a sports club. After finishing a gruelling exercise routine, he came out of the gym, felt dizzy and collapsed. People there tried to give him cardiac massage and lifted him to a nearby ICCU but he could not be revived and died in the prime of his life. Although a regular exerciser, he was a heavy smoker. His mother had undergone bypass surgery due to multiple blockages in her coronary arteries at age of 48 years (also called premature coronary artery disease).
    How is it that the same exercises that are supposed to help protect the heart actually lead to a heart attack?
CAN PHYSICAL EXERCISE CAUSE A HEART ATTACK?
In young people, (below age 25 to 30 years) the usual reason for sudden death related to vigorous exercise is the rare presence of a structural or electrical defect in the heart since birth or childhood which has gone unnoticed or undetected.
    However in people over 30, it is usually the fatty deposits on the inner lining of coronary arteries which supply blood to heart muscle, that are the cause. During and after vigorous (and especially unaccustomed) exertion, there is a surge in stress hormones like adrenaline and increased shear stress on coronary arteries. This may cause rupture of the surface of these fatty deposits (plaques). Also, vigorous exercise leads to the activation of blood cells called platelets. These can clump together and initiate clot formation at the site of the ruptured plaque in the coronary artery. This clot along with the fatty deposit can cause blockage or occlusion in the coronary artery, which leads to heart attack or sudden death.
WHY RISK THE HUFFING AND PUFFING? BEING A COUCH POTATO SEEMS SAFER
Studies have shown that unlike unaccustomed vigorous exercise, regular moderate level exercise (which gradually may be increased to higher intensity exercise) causes less stimulation of platelets and release of stress hormones. Also it stimulates the clot dissolving (fibrinolytic) property of blood. This benefit outweighs the propensity of platelets to clump during exercise and to cause clotting. Regular exercise also promotes increased vagal tone leading to better electrical stability of the heart so that there is less chance of irregular heart rhythm.