As if eating nine servings of fruits and veggies a day isn’t bad enough, now federal health experts are saying we need 60 to 90 minutes of exercise a day.

An article in today’s Seattle Post-Intelligencer tries to soften the blow by claiming that 30 minutes is enough for many people. The truth is, 30 minutes is enough to reduce the chances of chronic disease. But adults who want to prevent weight gain need 60 minutes a day on most days of the week; and adults trying to keep weight off need 90 minutes a day. Even worse, weight management requires boosting exercise but not caloric intake, which means that a workout won’t justify a bag of potato chips.

To my mind, the new recommendations are troubling (and not just because I love potato chips). In 1999, fully 61 percent of Americans were classified as overweight or obese, meaning that most people need at least an hour of exercise—and probably an hour and a half—on most days to be healthy. That’s a huge time commitment, especially in light of recent studies by the Centers for Disease Control that suggest that about one-quarter of Americans exercise almost not at all. And more than half—55 percent—do not reach the recommended minimum of 30 minutes a day on four days a week. (By the way, this definition of exercise even included light activities like sweeping and stretching.)

  • So not only must people make a lot of time for exercise, they must do so in busy schedules that may not currently accommodate fitness. It strikes me that only large-scale shifts in our lifestyles will allow us to get enough exercise.

    Luckily there may be policy remedies that can help address the persistently unhealthy lifestyles that many Americans are living. Specifically, policymakers can promote an urban form that prizes muscle power over internal combustion. (Interestingly, a recent study by the University of British Columbia demonstrated that dense neighborhoods encourage people to walk.) And it seems to me that from a public health perspective, we should seriously consider the notion that the environments we build—our cities and streets—can shape our behavior in ways that have direct implications for our waistlines and maybe even our lifelines.