Some activities such as snow shoveling, walking through heavy wet snow or in a snow drift, downhill and cross-country skiing, snow-boarding, can strain the heart enough to cause a heart attack. Snow shoveling can be more strenuous than exercising full throttle on a treadmill. Tips for Protecting Your Heart Before You Shovel Snow Avoid shoveling immediately after you awaken as most heart attacks occur early in the morning when blood is more prone to clotting. Wait for at least