There are plenty of obvious reasons to stay in good shape, but this information might give you even more motivation:

People who don’t exercise on a regular basis, and then have episodes of intense exercise or sex are more likely to experience a heart attack or die suddenly than those who are more active, new research suggests.

An analysis of 14 previous heart studies in this week’s Journal of the American Medical Association suggests that irregular bouts of physical activity can be a trigger for a heart attack or sudden death, while infrequent episodes of sexual activity increased the risk for just heart attacks. No studies looked at the association of sexual activity and sudden cardiac death.

As many as a million acute myocardial infarctions (heart attacks) and 300,000 cardiac arrests occur in the United States each year, according to the study authors.

The researchers found a 3.5 times increased risk of heart attack from episodic physical activity, while sex was associated with a 2.7 times greater risk.

This shouldn’t be a surprise. Too many people subject themselves to bursts of activity when they’re not ready for it, but these things happen in the normal course of life. Things like sex (hopefully) and shoveling the driveway will happen, and yet most people just aren’t in good enough shape. You won’t so these things well, and you might kill yourself in the process.

Get in shape!