Hey Americans, give yourself a big pat on the back.  Why?  Over 64% of adults were meeting the minimum level of aerobic physical activity in 2007.  That’s a 30% increase from 2005 when about 48% of men and women were getting the recommended amounts of physical activity.  Did Americans finally take the old Nike slogan to heart and, to paraphrase, “Just Did It?”

Not so fast.

What has accounted for this seemingly impressive gain in adults getting the recommended minimal amount of physical activity is simply a change in the way the government assessed physical activity.  In 2005, people were considered to be meeting the minimum public health requirement for physical activity if they were doing at least 30 minutes a day of moderate-intensity activity on 5 or more days a week, or at least 20 minutes a day of vigorous-intensity activity on 3 or more days a week, or both.

In the 2007 survey, adults were deemed “physically active” if they reported at least 150 minutes per week of moderate-intensity activity, or at least 75 minutes per week of vigorous-intensity activity, or a combination of  moderate-intensity and vigorous-intensity activity (multiplied by two) totaling at least 150 minutes per week.

So in the 2007 survey, simply taking away the requirement of a certain number of minutes on a certain number of days and allowing various combinations of moderate or vigorous or moderate AND vigorous activity to count boosted the proportion of physically active adults to an impressive 64%.

Which numbers should you believe?  It matters not.  The bottomline still remains that a large proportion of our adult population does not get adequate amounts of physical activity. 

Where do you fall in the active/not active spectrum??


Centers for Disease Control. Prevalence of self-reported physically active adults—United States, 2007.  Morbidity and Mortality Weekly.  2008;57:1297-1300

Centers for Disease Control. Prevalence of regular physical activity among adults—United States, 2001 and 2005.  Morbidity and Mortality Weekly.  MMWR. 2007;56:1209-1212