Exercising judgment: The psychology of fitness

Though it’s true that we are always looking for more ways to get people to exercise, Harvard professor Ellen Langer says it’s possible that some people are already getting more exercise than they realize.

The surgeon general recommends at least 30 minutes a day of moderate exercise or 20 minutes of vigorous exercise three times a week. But those numbers are based on white-collar workers. Construction workers, for example, spend most of their day lifting and pushing and pulling. Trash collectors are often running from the truck to the sidewalk. And hotel cleaning attendants are running around rooms quickly and vigorously scrubbing bathrooms.

It’s this last group that Langer and her student, Alia J. Crum, looked at in a 2007 study. Langer and Crum went to a variety of hotels to recruit volunteers from the cleaning staffs. They told one group that the work they were doing was already enough exercise to meet the surgeon general’s daily requirements. Changing linen for 15 minutes burns approximately 40 calories, they told the attendants. And vacuuming for 15 minutes burns about 50 calories. The other group was not given this knowledge. When they returned to the hotels four weeks later, Langer and Crum found that the informed group showed a decrease in weight, blood pressure, body fat, waist-to-hip ratio, and body mass index.

It is possible that the people who were told about the health benefits of their work made other changes to their behavior, such as dieting or increased workload at the hotels. But all the room attendants were asked to report on these activities, and they did not report any changes. They simply became healthier just by being mindful of what they were doing.

“People are mindless with respect to most other exertion,” Langer says. “People see themselves when they’re eating. They don’t pay attention to the amount of calories burned standing there and stirring. … I think this study reveals that we potentially have far more control over our psychological and physical functioning than most of us realize.”

Langer has an anecdote that she tells when talking about this subject. She walks into a gym and sees a sign that says “Stairmaster on third floor.” Many people, Langer hypothesizes, would consider their 20-minute Stairmaster workout — and not their three-flight walk up to it — their only exercise of the day.

So is it possible that most of us are actually getting more exercise than we think" Think about a typical day where you walk to the bus stop, walk to lunch, walk to the copying machine, walk through the supermarket on your way home, and walk around the kitchen while cooking dinner and setting the table. Even a Saturday of sitting around on your couch and watching college football probably involves a walk down to the store for some soda and chips and maybe a game of catch at halftime.