SLIPPERY ROCK — As deer season gets under way Monday, three Slippery Rock University exercise and rehabilitative science professors have a research-backed message for hunters and their families: It’s not the cold or miles of walking that pose the greatest cardiac risk, it’s dragging the deer out of the woods.

Steve Verba and Brock Jensen, assistant professors, and Jeff Lynn, associate professor, have published “Dynamic heart rate response to deer hunting in men and women.”

While more than 14 million Americans engage in some form of hunting annually, professors said they found only three other published studies looking at deer hunting risks.

None included women hunters as subjects; SRU’s yearlong study involved 12 men and seven women.

Verba said the testing showed women’s heart rates increase more than men’s during the drag phase, but all hunters are at risk.

Hunting deaths by a stray bullet or falling out of a tree stand attract the most media coverage, but hunters are more likely to die from a heart attack, especially when hauling their kill back to the vehicles.

“You look at the newspaper or watch the news you see, a hunter has some event in the woods, or even has a heart attack and dies,” Verba said. “The more you start thinking about it, the more you realize this is something that happens ever year and should be studied.”

The professors said they are not against hunting as a recreational activity or exercise method but urge hunters to exercise caution.

Hunters should see a doctor for a checkup before suiting up in camouflage and heading into the woods. They should also consider preseason cardio training. Hunters should drag a deer a little ways and then rest for a couple of minutes. Other tips include using an all-terrain vehicle or other hauling device.

Pulling a deer, which can weigh more than 200 pounds, amounts to high-intensity exercise. This can be dangerous, especially for those with heart disease, because a sudden and extreme rise in heart rate can lead to a cardiac event, including heart attack.

“What it came down to is we know the most strenuous part of this (hunting) is dragging the deer,” Verba said.

Phase one of the study, a simulated hunt accomplished with a 120-pound “sandbag deer” dragged in the woods behind the SRU ski lodge, measured the force needed to drag a deer and how that affected the person’s heart rate.

For phase two, hunters ages 18-60 wore a wireless electrocardiogram so that professors could measure heart rate and rhythm during an actual hunt.

Professors said “buck fever” accounts for some of the danger. This is an adrenaline rush many hunters get upon spotting a deer, firing and killing the animal.

“If you were lucky enough to get one, then the work starts. I know this from personal experience” Verba said. “You go through all this excitement of shooting a deer and now it’s like, ‘I have to get this thing out of here.’ All of a sudden, you have to drag this 120-pound animal. Depending on where you were and how far you have to drag the animal, it turns into a real chore.

“To a certain extent, you have to listen to your body,” he said. “If you start to feel overwhelmed, certainly take a break.”

Said Lynn, “When people see the target and they’re drawing down on the deer with their rifle, they all describe this feeling of barely being able to catch their breath and their heart rate skyrockets. Interestingly, that is exactly what people describe when they’re having a heart attack.”

He compared deer-dragging exertion to a sprint, saying heart rate can spike from a resting heart rate to a near maximum heart rate in 90 seconds.

“If you’re gutting a deer, and you get up and start dragging it, it would be like sitting in your chair and just getting up and sprinting a 200-yard dash,” Lynn said. “By knowing that now, as a hunter, you should realize that you need to exercise some caution. Pull a little, then rest, pull a little, then rest, without overdoing it.”

Verba said he served as principal investigator for the study. Lynn and Jenson helped brainstorm the idea, collect data and analyze the results to prepare the manuscript. Their paper was accepted for publication in October for the online version of Comparative Exercise Physiology.

“Brock and I both hunt and come from hunting families, so it’s a topic that’s near and dear to both of us,” Verba said.

Verba reiterated that the weight of a deer carries the greatest risk of a deer hunting heart trauma.

“In young, healthy, active men and women, the hiking phase of deer hunting does not constitute high-intensity exercise,” he said.

“However, dragging a deer is high-intensity for both sexes and appears to have a greater relative stress on women,” he said.