Watching your step
Scientists are using the Grand Canyon as a lab for studying human performance under extreme conditions
Have you added hiking the Grand Canyon to your bucket list? More and more people have, researchers say.
Last year, the National Park Service counted more than 5.9 million visitors to the Grand Canyon, and this year by August more than 5.5 million people had already visited.
Despite the extreme physical demands of hiking the 20-plus miles rim-to-rim, many people just aren’t prepared and suffer dire consequences. Some die. Hundreds of others suffer an emergency and have to be rescued, either airlifted or walked out of the canyon.
On a peak weekend day, as many as 1,000 people are hiking, says Emily Pearce, a paramedic, medical student and former search-and-rescue ranger at Grand Canyon National Park. Rangers respond to about 300 incidents a year, and about half of those require a helicopter evacuation.
“Many of these are highly preventable, if people hike smart and make smart decisions,” Pearce says. “We want people to see the Grand Canyon — have fun and stay safe. They would do better if they dialed back their expectations.”
Pearce and other researchers from the University of New Mexico School of Medicine and Sandia National Laboratories are studying all kinds of Grand Canyon hikers to understand how people react physically and mentally to these challenging conditions.
They’ll share their findings in a free lecture 6:30-7:45 p.m. Nov. 8 at the Albuquerque Academy.
Dr. Jon Femling, an emergency physician and assistant professor at the UNM School of Medicine, says researchers see it all — from successful outcomes to those who hit the wall.
“It’s an extreme activity; people are going to get tired,” he says. “We see folks in their 70s and 80s crossing the canyon looking better when they come out than hikers in their 20s. The people who do the best have previous experience, mental fortitude and grit.”
One aspect many hikers don’t consider is that the second half of the hike is the most grueling, climbing uphill, an elevation increase of about a mile. It can compound the cognitive changes and bad decision-making that can come from physical stress, he says.
Also, most hikers start at dawn, but that means the trek out is during the hottest part of the day, he says. Temperatures in the Grand Canyon are generally about 20 degrees higher at the bottom and can range from 30 degrees to 120 degrees.
A research team heads to the Grand Canyon twice a year, in May and October, and recruits volunteers who are starting their hikes. Some coordinate their hikes through the Facebook Grand Canyon Rim-to-Rim WATCH Study page. The three-year study, Rimto-Rim Wearables at the Canyon for Health, is funded through the Defense Threat Reduction Agency, part of the Department of Defense.
Volunteers complete a survey, some also wear tracking devices that collect medical and physical exertion information, and some volunteers also provide blood samples. They are assessed at the beginning, the bottom of the canyon and at the rim again.
Cathy Branda, PhD, a senior manager in Applied Biosciences and Engineering at Sandia National Laboratories in Livermore, Calif., says the wearables are limited by how well the wearer listens to the feedback and adjusts food intake and activity.
The study will benefit all those in extreme conditions, she says, including soldiers in the field.
She is also interested in cognitive clues that can be measured before an illness. Feeling spacey can be the first sign of flu, for example. And if a soldier can understand that, he can keep himself and others safer.
Hyponatremia, over-hydration without adequate replacement of electrolyte salts, can be a problem, but the wearables can help hikers monitor that, Branda says.
Otherwise hyponatremia can result in disorientation or worse if not treated.
Reading the wearables correctly could mean the hiker knows when she needs to eat a banana or a Slim Jim, for example, to boost the body with electrolytes, Femling says.
But it boils down to the individual, he adds. “Someone from Iowa needs more water and salts than someone who lives here.”