Submitted by: agcomm,  Thu Nov 20 09:45:32 1997


                        November 20, 1997
 
NDSU Research on Snow Shoveling Uncovers Questions 
about Intensity 
 
     Shoveling snow burns about 150 calories an hour, research
done at North Dakota State University shows. The NDSU study
confirms the portion of the U.S. Surgeon General's landmark 1996
report on physical activity and health that lists snow shoveling
as a moderate activity. But last winter's study involving a group
of 21-year-old NDSU students now has the researchers asking more
questions.
     "Maybe snow shoveling is more intense than the Surgeon
General's report says it is," says Donna Terbizan, an associate
professor in NDSU's health, physical education and recreation
department. "These were young, healthy adults in our study. Would
the results be different for older, out-of-shape adults? My guess
is yes, but we've got no data yet to support that."
     While preliminary, the NDSU research does help crystallize
some common-sense information that all snow shovelers should
heed. Namely, don't work too hard or too fast. Plan ahead so
breaks can become part of the snow shoveling routine. By keeping
heart rates within safe levels, those breaks can be life savers.
     Snow shovelers should take extended breaks so they don't
become fatigued, Terbizan says. The reason? Fatigue and exertion
both increase a person's heart rate. The message? Don't push
beyond certain points of physical exertion. Screaming muscles and
an aching back are body language worth listening to.
     "Stubbornness can be a problem," says Terbizan.
     Working with Terbizan on last year's study were Brad Strand,
chair of the NDSU health, physical education and recreation
department, and Denis "Izzy" Isrow, a professor in the
department. They measured the impact that two types of activity
had on the heart rates of 12 male and three female volunteers who
had an average resting heart rate of 66 beats a minute.
     First, the students walked one mile on an indoor track as
fast as possible. Afterward, the students rested about 10
minutes, until their heart rates slowed to 110 beats per minute.
Then the students went outdoors and shoveled snow for 14 minutes.
Using a flat snow shovel with a 16-inch face, each student
shoveled drifted snow by throwing it over a 4-foot fence, an
action designed to mimic typical snow shoveling activities.
     During the experiment, the students wore straps around their
chests containing an electronic sensor which relayed signals to a
computerized wrist watch. The researchers then downloaded the
data for final evaluation. 
     "When the students were shoveling snow, their heart rates
went up within about two minutes from when they started and then
stayed there," says Terbizan. "During the walk, the students'
heart rates increased more steadily while they were walking, so
that adds to the information about how strenuous snow shoveling
can be."
     The students spent nearly 41 percent of their time during
their walk at a moderate- intensity heart rate level (50 to 70
percent of capacity) compared to about 54 percent when they
shoveled snow. The average heart rate was nearly 131 beats per
minute for walking and 153 beats per minute while shoveling. The
snow shoveling also caused the students' heart rates to spend
more time in a higher-intensity range, from 70 to more than 90
percent of capacity. By comparison, students spent less than 21
percent of their time at those levels when walking.               
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NDSU Agriculture Communication
Source: Donna Terbizan (701) 231-7792
Editor: Dean Hulse (701) 231-6136