Shoveling snow is a physically demanding activity that can put significant strain on the heart, according to medical experts. The exertion involved uses large muscle groups and requires trunk rotation, making it an aerobic exercise that can quickly outpace the heart’s capacity, especially for those who are not regularly active.
Dr. Glazier and Dr. Ko, both with experience in regions prone to heavy snowfall, have observed numerous cases of cardiac issues related to snow shoveling. They explain that physical exertion is measured in metabolic equivalents (METs), a scale where sitting quietly equals one MET and intense activities like sprinting reach up to 18 or 20 METs. Shoveling snow typically falls between 5 and 7 METs—similar to playing vigorous doubles tennis—and marks the transition from moderate to vigorous activity levels.
At this intensity, cardiovascular demand increases sharply, often without individuals noticing until warning signs appear. These symptoms may include shortness of breath, weakness, dizziness, chest pressure or pain, irregular heartbeat, nausea, or sudden fatigue. In cold weather conditions, blood vessels near the skin constrict—a process called cold-induced peripheral vasoconstriction—which raises blood pressure and adds further risk during strenuous activities like shoveling.
Exercise physiologists note that just two minutes of shoveling can raise heart rates above 85% of their maximum—a level comparable to what is seen during a cardiac stress test.
To reduce risk while shoveling snow:
– Work at a slow to moderate pace.
– Take frequent breaks.
– Push or sweep snow rather than lifting it when possible.
– Avoid overfilling the shovel.
– Remember to breathe steadily throughout the activity.
“If you experience any of the symptoms we noted above,” Dr. Glazier and Dr. Ko advise, “stop immediately.” They also caution that anyone living with heart disease or who has risk factors for heart disease should avoid shoveling snow altogether.
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