"To get to be a Hot Shot to begin with is incredibly difficult," said study leader Dan Heil, an exercise physiology professor at Montana State University in Bozeman. "But once there, these individuals pride themselves on being the hardest workers and the most reliable workers."
Keeping the elite firefighters, who work long, hot days in steep terrain carrying heavy loads, properly fueled and hydrated is the focus of ongoing studies funded by the U.S. Forest Service.
Heil's report, published in Applied Ergonomics, shows that electronic activity monitors worn in firefighter's shirt pockets are just as accurate as using urine samples to measure how many calories crew members expend.
"It's not a lot of fun," Heil said of the technique that required researchers to collect urine samples for days. Although accurate, the urine analysis is expensive and doesn't show patterns or bursts of activity that occur throughout the day.
"We need more information to understand how individual bouts of activity and individual behavioral patterns contribute to total daily energy expenditures," Heil said.
Heil had 10 Hot Shots from the Helena-based crew wear the matchbook-sized activity monitors in their chest pockets for 21 consecutive days during the grueling 2000 fire season.
Measuring mostly upper-body movements, the monitors recorded activity data once per minute. Electronic sensors measure changes in velocity, making the monitors more accurate than pedometers, which register simple up-and-down movements with a pendulum. Heil downloaded the data from the monitors and analyzed the results.
He found that the firefighters burned calories on par with Marines conducting cold-weather field exercises; with an Army platoon training for jungle warfare; and with mountain climbers scaling Mount Shisha Pangma in the Himalayas.
Finding out he burns calories like a soldier or mountain climber came as no surprise to Travis Pfister, 25, of Missoula.
A firefighter with the Lolo Interagency Hot Shot crew, Pfister said he carries about 70 pounds of equipment, including a chain saw, fuel and tools. The terrain can vary from relatively flat to a 40 percent grade, and the shifts can vary from eight hours to up to 16 hours a day.
"It's a pretty cool little project," Pfister said of the research. "They're concerned about our nutrition and trying to make sure we get enough of everything so we can keep doing this and stay healthy."
Last summer Heil helped scientists at the University of Montana monitor firefighters' blood glucose levels to better understand how well the firefighters' food consumption matched their energy expenditures.
Next summer he may help the same research team evaluate how well the Hot Shots monitor their hydration levels. The studies could give managers an objective way of dictating when crews take breaks.
"These are two more layers [of information] to see how well firefighters are doing," Heil explained. "They'll work themselves to the bone before they'll say they're tired."
Contact: Dan Heil, (406) 994-6324 or email@example.com