Persevering on the Appalachian Trail
Thru-hiking the 2,175-mile Appalachian Trail results in greater aerobic fitness and lower cardiovascular stress, according to a research study by an Alma College research team. Most hikers also maintain appropriate nutrient levels.
In addition, initial
aerobic fitness, body composition and body weight are all good
predictors of success in completing a thru-hike of the Appalachian
Mountains.
“Individuals preparing to embark on the hike should consider these factors in training for the hike,” says lead researcher John Davis, professor of exercise and health science at Alma College.
A thru-hiker tests his endurance for John Davis (in the background).
Davis and a team of students investigated the physiological and nutritional challenges that thru-hikers faced during the spring and summer of 2007. They conducted a series of tests — including heart rate, blood pressure, aerobic fitness, body composition and muscle strength — on hikers before they started on the trail in March, during their hike at locations along the way, and at the conclusion of the trip in September.
The
research results were not necessarily surprising to Davis and his
students. Yet, no previous studies had examined the physiological and
nutritional changes that occur as a result of hiking the entire trail.
Typically, less than 25 percent of individuals who start the hike
complete it.
“This information will be helpful to the scientific community
and future long distance hikers,” says Davis. “It helps answer the
question: How far can humans push themselves?
“The hike along the Appalachian Trail is one of the toughest
ultra endurance activities that occurs – hiking day-after-day, about 15
to 20 miles a day, for four to five months,” says Davis. “I’ve always
been interested in the limits of human performance and the kinds of
changes that take place during this kind of endurance activity. This
research is a good fit for my academic interest.”
John Davis tests a thru-hiker for aerobic fitness.
Davis tested the effects of hiking the trail by measuring oxygen consumption and heart rate during a graded exercise test. As expected, he found that aerobic capacity increased and heart rates decreased in response to hiking an average of 519 miles on the trail.
“We found that
hikers’ ability to deliver oxygen to tissues increases after time spent
on the trail,” says Davis. “This is a positive adaptation to the daily
physical demands of hiking the Appalachian Trail and is reflected in
reduced cardiovascular stress during exercise. In a nutshell, their
overall cardiovascular fitness improved, allowing them to adjust to
hiking daily long distances.”
Davis also surveyed the thru-hikers on their diets and measured
their carbohydrate, fat and protein levels. He found that the
thru-hikers maintained an acceptable amount of macronutrients in their
diets, and that the percentage of fats was only slightly above normal
ranges. In addition, subjects experience a substantial negative caloric
deficit that resulted in only a five-pound weight loss.
“The lack of a significant weight loss probably reflects the
eating strategies on and off the trail,” says Davis. “Most thru-hikers
don’t eat much on the trail but binge off the trail.”
Davis found two strategies for training. Some do very little
preparation and “get fit as they go.” Others undergo serious
preparation for the physical challenges of the trail. Davis tested 51
thru-hikers the day before they started their hike, measuring oxygen
consumption, percentage of body fat and body weight. Thirty-one
subjects out of the 51 ultimately completed the entire 2,175 miles.
“We found that to increase their chances of successfully
completing a thru-hike, hikers should consider lowering their body
weight and percentage of body fat and increasing aerobic fitness before
starting their hike,” says Davis.
The reasons some hikers abandon their quest along the way are
often psychological or personal as opposed to physiological, says Davis.
“If you persevere and are tough psychologically, you can overcome,” he says.
Pre-testing was performed in March and April at the Hiker Hostel in Dahlonega, Georgia.
Mid-testing
was done in May throughout Virginia and Northern Tennessee.
Post-testing was completed at the AT Lodge in Millinocket, Maine.
• Total length: 2,175 miles
• Highest point: Clingman’s Dome, 6,000 feet
• Passes through 14 states
• Total elevation change: 90 miles
• In 2005, only 25 percent completed the entire trail
• Speed record: 47 days, 13 hours, 31 minutes in 2005
• Physically demanding: 5,739,500 steps, 21.6 million heart beats
Posted: Mon, March 31st, 2008 at 1:47PM
