EAST LANSING, Mich. – If you’re a man of around 40, or a woman in the vicinity of 50 and you feel guilty about asking your son or daughter to shovel the snow off your driveway or sidewalk, don’t worry, it’s probably good for them.
Research at Michigan State University has found that when younger people shovel wet, heavy snow, there is an increase in the level of an enzyme in the blood that can help fight the effects of coagulation, which causes blood clots.
“This is very important because it’s usually a blood clot that causes the final stage of a heart attack,” said Christopher Womack, an assistant professor of kinesiology at MSU and one of the researchers.
Womack and his colleagues were surprised by this finding, and also by something that they didn’t find. They had expected to find that heavy-duty snow shoveling would increase the potential for blood coagulation, such as it does when a person does a high-exertion aerobic workout.
“We thought we’d see the type of response we see with strength training or any other kind of heavy, upper-body lifting,” he said. “But we didn’t find that at all. Instead, we found an increase in the level of enzymes that help prevent coagulation.”
Then why so many stories in the news about people dying from heart attacks while shoveling snow? Womack said it probably has more to do with the age of the shoveler.
“When a man reaches the age of 40 or so, and a woman 50, blood coagulation potential starts to change,” he said. “Generally speaking, that’s about the time you might want to hire the son or daughter or grandchildren to do the snow shoveling.”
As people get older, he said, their blood has more of a tendency to coagulate, which can cause blood clots. At the same time, the blood loses some of the enzymes that can break down clots that do form.
To do the research, Womack and his colleagues had about a dozen healthy men, all around the age of 25, shovel a driveway that had been filled with snow that was scraped off an ice rink by a Zamboni. After 10 minutes of shoveling, blood samples were taken. The men then did 10 minutes' worth of shoveling using a snow blower. Again, blood samples were taken.
“Even though we found, at least in these healthy, young guys, that snow shoveling by hand is more stressful, it didn’t change their coagulation potential at all,” Womack said. “This tells me that, at least in this population, they can go out and shovel away.”
Other collaborators in this project were Chad Paton, Adam Coughlin and Paul Nagelkirk, all from the MSU Department of Kinesiology; and Adam DeJong, Jamie Anderson and Barry Franklin, all from the Cardiac Rehabilitation and Exercise Laboratories, William Beaumont Hospital, Royal Oak, Mich.
The findings were published in Medicine and Science in Sports and Exercise, the official journal of the American College of Sports Medicine.