Steps in the right direction

Fitness recommendations almost always sound manufactured: Exercise at least five times a week. Keep heart rate elevated for more than 30 minutes for optimal effect. Take several minutes to warm up and to cool down.

The standard advice for walking fitness -- take 10,000 steps a day -- seems especially tidy.

But that doesn’t mean it’s wrong.

Researchers are finding evidence that 10,000 steps in a day do represent a significant, if rough, threshold for physical fitness.

At the University of Tennessee in Knoxville, physiologists recently asked 80 women between ages 40 and 60 to wear a pedometer every day for a week. The investigators measured the women’s weight, height, body fat, waist and hip sizes. They then calculated the average number of steps each woman took over the course of a day.

“These were women at precisely the stage of life when they put on extra pounds and put themselves at increased risk for heart disease and diabetes,” said physiologist Dixie Thompson, the study’s lead author and director of the University of Tennessee’s Center for Physical Activity and Health.

After a week, a clear pattern emerged: The women who averaged more than 10,000 steps a day had 40% less body fat, and waist and hip measurements that were four to six inches narrower than those who averaged fewer than 6,000 steps.

The study does not prove that the walking caused the differences in body composition. Yet other studies have shown that sedentary women who begin walking 10,000 steps a day shed several pounds within a few weeks and reduce their blood pressure. Six thousand steps add up to about three miles, which is what the average adult walks during a typical day of working, doing chores or taking care of children.

To add 4,000 more requires conscious exercise, physiologists say. The most fit women in the Tennessee study either took regular exercise walks, strolled long distances with their dog or made an effort to walk to shops and appointments.

It’s no coincidence that this added activity takes about 30 minutes a day, which is the recommended minimum to achieve fitness. The 10,000-steps regimen first took hold in Japan in the 1960s, after researchers there noticed that men and women who walked that much every day were noticeably healthier than those who walked less.

“What I would say is that while there may not be a magic step recommendation for everyone, 10,000 looks right now like a very good target,” said Thompson, “and it’s certainly a good one for middle-aged women who want to control their weight and blood pressure.”