When you picture dangerous winter activities, do you think of skiing or maybe snowboarding? You may be surprised that, on average, only 38 Americans are killed each year in skiing and snowboarding accidents combined, compared to 100 deaths in the U.S. related to shoveling snow.

How can shoveling be so dangerous?

Think of a primarily sedentary 50-year-old man gulping down his coffee so he can go out on a cold morning to move hundreds of pounds of snow before he has to leave for work. He’s putting a lot of strain on his upper body in particular, in an aerobic activity that’s more strenuous than many sports. And he’s doing this while inhaling cold air.

The combination of an intense, unfamiliar exertion and cold air taxes the heart because it boosts blood pressure and heart rate, as well as the demand for oxygen. The cold also can make blood vessels constrict.

A Harvard Health blog posted by Robert Shmerling, M.D., refers to a study that he says suggests people avoid shoveling if they have heart disease or a high risk for it. The study found that the deeper the snow, the more men died of heart attacks, and Dr. Shmerling agrees that the most plausible explanation for this increase is that they were shoveling snow.

If you are going to shovel snow this season, here’s how you can reduce your risk:

• Avoid shoveling in the early morning when heart attacks most often occur.
• March in place or otherwise warm up your muscles before shoveling.
• Don’t shovel soon after eating a heavy meal, drinking caffeinated beverages or smoking.
• Pace yourself, taking breaks every 15 minutes.
• When possible, push the snow, rather than lift it. When you do lift, pick up only a small amount at a time.
• Cover your head, and wear layers and skid-resistant footwear.
• Shovel the snow when it’s still fresh and powdery.
• It’s okay to use a shovel that’s 24 inches wide for light snow, but use a narrower, lighter model when snow is wet and heavy. Consider owning a variety of shovels for different uses.
• Check with your doctor before shoveling if you’re sedentary and over 40, especially if you have risk factors or a history of heart disease.
• If you do experience chest pain, dizziness or other symptoms of a heart attack, chew an aspirin and call 911.

Learn more about how to lower your risk of heart disease.