[PHNUTR-L] Walk slowly for weight loss, according to University of Colorado study

[Kathrynne Holden, MS, RD]

Colleagues, the following is FYI and does not necessarily reflect my own
opinion. I have no further knowledge of the topic.
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Public release date: 15-Jun-2005
http://www.eurekalert.org/pub_releases/2005-06/uoca-wsf061505.php

Contact: Ray Browning
browning at colorado.edu
303-492-0926

Rodger Kram
Rodger.kram at colorado.edu
303-492-7984

Jim Scott
303-492-3114

University of Colorado

Walk slowly for weight loss, according to University of Colorado study

Leisurely walking for distance combined with low-impact cardiovascular 
activity appears to be the best formula for obese people seeking to get 
into shape and stay healthy, according to a University of Colorado at 
Boulder study.

Ray Browning, a doctoral student in CU-Boulder's integrative physiology 
department and lead author on the new study, said the results show that 
people who walk a mile at a leisurely pace burn more calories than if 
they walk a mile at their normal pace. In addition, those who walk at 2 
miles per hour rather than 3 miles per hour reduce the loads on their 
knee joints by up to 25 percent.

"The message is that by walking more slowly, obese individuals can burn 
more calories per mile and may reduce the risk of arthritis or joint 
injury," he said.

Browning and his CU colleagues also found the number of calories burned 
per pound of body weight is similar for obese adults as normal sized 
adults walking at the same speed. Because obese people generally have 
heavier legs, wider stances and swing their legs in a wider arc, the 
researchers expected the cost of walking for obese people to be 
significantly higher.

"This was a surprise," said Browning. "The subjects probably are 
unwittingly altering their posture and walking with straighter legs, 
conserving calories in the process."

A paper by Browning, CU-Boulder integrative physiology Associate 
Professor Rodger Kram and undergraduates Emily Baker and Jessica Herron 
was presented at the June 2005 meeting of the American College of Sports 
Medicine meeting in Nashville and published recently in the journal, 
"Obesity Research."

The CU-Boulder researchers based their expectations that obese adults 
would have a greater energy cost when walking on previous studies by 
Kram's lab team. In one study, energy expenditure increased by about 25 
percent when normal-weight people walked with a deliberately wider 
stance, said Browning.

Other CU studies conducted in CU's Locomotion Laboratory have shown that 
normal weight people wearing "winged" shoes designed to force them to 
increase their lateral leg swing increased the metabolic cost of walking 
by 30 percent, Browning said.

"As people become gradually obese, they also seem to become particularly 
graceful," said Kram. "There appears to be some sort of a physiological 
drive for them to minimize the amount of energy they expend."

The researchers tested 20 men and 20 women on treadmills and sidewalks, 
half of whom were of normal weight and half classified as class 2 obese, 
meaning they have a body mass index, or BMI, of 30 to 40. A 5-foot 
4-inch tall woman with a BMI of 30 weighs about 175 pounds, while a 
6-foot man with a BMI of 30 weighs about 225 pounds.

The researchers measured each subject's body composition using an 
instrument known as a DEXA scanner to measure fat mass, lean tissue mass 
and bone mineral content of the total body. They also measured the 
oxygen consumption and carbon dioxide production of the test subjects to 
determine the energy and calories expended while walking.

As part of the ongoing research, the research team is using a unique 
treadmill that can independently measure loads placed on the left and 
right feet while walking, Browning said. The treadmill helps them 
measure how the biomechanical forces increase with body weight and 
walking speed.

The results show that brisk walking dramatically increases the knee 
joint forces, which can lead to a variety of problems including joint 
injuries and arthritis, the researchers said.

"This study also pointed up the phenomenal accomplishments of obese 
people," said Kram. "Our test subjects lead productive lives, and if you 
weigh 300 pounds, many everyday activities are athletic endeavors."

Walking doesn't require special clothing, stressed Browning. "It's doing 
some simple things, like using the stairs rather the elevator, parking 
your car further from your destination, or getting off the bus one stop 
early and walking. Rather than trying to walk fast, obese individuals 
can gain both caloric and biomechanical benefits from walking at a more 
leisurely pace."

Because walking slowly may not significantly improve an obese person's 
level of cardiovascular fitness, performing other vigorous lower-impact 
activities like swimming, cycling, step routines and elliptical training 
workouts also are recommended, said Browning.

Much of the research was carried out at the General Clinical Research 
Center housed within CU-Boulder's Wardenburg Health Center, which 
receives more than $1 million in funding annually from the National 
Institutes of Health.
-- 
Kathrynne Holden, MS, RD < fivestar at nutritionucanlivewith.com >
"Ask the Parkinson Dietitian"  http://www.parkinson.org/
"Eat well, stay well with Parkinson's disease"
"Parkinson's disease: Guidelines for Medical Nutrition Therapy"
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