In India, there has been an increasing trend, in urban areas in particular, of non-athletes taking up running or gymming in middle-age. Some of them may already have risk factors for heart disease. Many of these enthusiasts train intermittently and often without professional supervision. Intense exercise or sudden bursts of exercise increase the risks of heart attacks and sudden deaths during and soon after the exercise. In general, people should start getting used to exercise early in life. For those over 35, or with symptoms or risk factors like a family history, high blood pressure, I recommend a formal medical evaluation and go-ahead from a physician. When commencing exercise, starting low and going slow with professional supervision is safer. I would also advise these enthusiasts to bear in mind that most of the cardiovascular benefits of exercise accrue with moderate exercise (in intensity, frequency and duration) after which there are diminishing returns and even possible harm with heavy exercise. It should also be noted that while exercise can provide health benefits, it does not provide immunity from heart disease or heart attacks.