Let's say you're an aging athlete who's out skate-skiing. Let's say you get home and discover that another aging athlete you know just had a heart attack doing the same thing, OK, let's say you're me.

You hear that one of former mayor R.T. Rybak's symptoms was shortness of breath, which comes with the territory when you're skating up a hill.

Here's some guidance on how to tell the difference, just in time for this weekend's City of Lakes Loppet ski fest, for which Rybak was training.

It turns out that trouble breathing was only one of Rybak's symptoms, he told this writer recently. "It was a cold day, and I felt like someone had put an ice pack on my heart…As I was climbing a hill, I felt, 'I have far less strength,' and when I got to the top of the hill, I knew something was wrong but I couldn't quantify it. When I got back to the car, I lost the ability to breathe, but I never felt a stabbing in my heart…It felt more like there was an elephant sitting on my chest."

"I did not think I was having a heart attack. I thought something was very, very wrong."
He demonstrated three keys that may accompany a heart attack: shortness of breath, weakness or loss of strength, and chest pressure. All are classic symptoms. Exercise and cold weather can also trigger the chest-squeezing feeling known as angina that Rybak experienced. But not every heart attack is the same.

"The doctors have told me when I talk about this to recognize that it's different in everybody," cautioned Rybak, who had a family predisposition to heart disease.

Kevin Harris, a cardiologist with Minneapolis Heart Institute, used to operate with the assumption that endurance sports provided protection against heart disease for participants. Indeed, a 2012 review of data published in the New England Journal of Medicine did find what it called a low overall risk (.54 per 100,000 participants) of cardiac arrest and sudden death among U.S. marathon and half-marathon participants.

But there's no absolute immunity. Fifty nine participants over a 10-1/2-year period had heart attacks, with 71 percent fatal. And even elite athletes are susceptible, as proved by the massive 1992 heart attack that felled Minneapolitan and 1968 Olympic marathoner Ron Daws at age 55. Three of his coronary arteries were partially blocked.

Athletes know their bodies best, Harris said, but they may want to consider a stress test, especially those over 40. A basic test hooks up a runner with an electrocardiogram to look for abnormalities that may indicate a blockage. More sophisticated tests add imaging to the detective work.

Harris urges athletes to look for symptoms out of the ordinary during their exertion, with a sense of a weight on the chest being the classic sign. Athletes can also analyze risk factors: hypertension, family history, high cholesterol and so on. "There's certain things you can correct, but certain things you can't get away from," he said.

(Photos above: Rybak skiing, and Ron Daws)