Updated

A slower-than-normal walk may offer obese men and women a better bang for their buck when it comes to burning calories and avoiding knee injuries.

Researchers found that obese people who walk at a slower pace burn more calories than when they walk at their normal pace. In addition, walking at a slower, 2-mile-per-hour pace reduces the stress on their knee joints by up to 25 percent compared with walking at a brisk 3-mile-per-hour pace.

"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," says researcher Ray Browning, a doctoral student in integrative physiology at the University of Colorado, Boulder, in a news release.

The results appear in a recent issue of the journal Obesity Research.

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Walk Slow, Burn More Calories

In the study, researchers tested 20 men and 20 women on treadmills and sidewalks to see how many calories they burned walking at different speeds. They also determined their posture while walking.

Half of the participants were obese and half were of normal weight.

Researchers found that the obese people burned more calories when walking at the same speed as normal-weight walkers.

This may be because obese people usually have heavier legs and wider stances, which causes them to swing their legs out more, making walking more work for obese people. They also say obesity leads to postural instability, so obese people require more muscles during walking to compensate.

They also found that normal-pace walking significantly increased forces on the knee by about 25 percent compared with slower walking, which could lead to joint injuries or arthritis.

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Exercise Prescription

Therefore, the researchers say that obese people gain a net benefit -- burning calories plus decreasing joint stress -- by walking slower than normal. Walking slowly for a longer period of time slightly increases the number of calories burned, they add.

They suggest that walking 2 miles an hour may be more beneficial for obese people than a more normal pace of 3 miles an hour.

Although walking slowly may help obese men and women burn calories more efficiently, researchers say walking slowly does not offer much in the way of cardiovascular benefits. Therefore, they advise a combination of walking slowly and other vigorous low-impact activities, such as swimming, cycling, and elliptical training workouts for optimum health.

Read WebMD's "Better Late Than Never for Exercise"

By Jennifer Warner, reviewed by Michael W. Smith, MD

SOURCES: Browning, R. Obesity Research, May 2005; vol 13: pp 891-899. News release, University of Colorado.