"Picking up a shovel and moving hundreds of pounds of snow, particularly after doing nothing physical for several months, can put a big strain on the heart," the Harvard Health newsletter said. "Pushing a heavy snow blower can do the same thing. Cold weather is another contributor because it can boost blood pressure, interrupt blood flow to part of the heart, and make blood more likely to form clots."
Researchers said a heart attack occurs when a clot forms inside a coronary artery -- a vessel that nourishes the heart. The clot can completely block blood flow to part of the heart and it is after this cut off of oxygen and nutrients that heart muscle cells begin to shut down, and then die.
Snow shoveling is more strenuous than exercising full throttle on a treadmill, which is usually not a problem for the young and fit, but can be life threatening for those age 50 and older or those not active, the newsletter said.
Research at the University of Virginia Medical Center suggested anyone who has received an artery-opening stent in the preceding year might want to be especially careful about clearing snow, the newsletter said.
Experts recommend older adults find someone younger to shovel the driveway and everyone else to:
-- Warm up your muscles before starting.
-- Shovel many light loads instead of fewer heavy ones.
-- Take frequent breaks.
-- Drink plenty of water.
-- Don't feel that you need to clear every speck of snow.
-- Head indoors right away if your chest starts hurting, you feel lightheaded or short of breath, your heart starts racing, or some other physical change makes you nervous. If you think you are having a heart attack, call 911.