December 5, 2008 / 57(48);1297-1300
Prevalence of Self-Reported Physically Active Adults --- United States, 2007
Physical Activity Guidelines for Americans
(2008 Guidelines), released in October by the U.S. Department of
Health and Human Services, provides new guidelines for aerobic physical
activity (i.e., activity that increases breathing and heart rate) and
muscle strengthening physical activity (
1). Under the 2008 Guidelines, the minimum recommended aerobic
physical activity required to produce substantial health benefits in
adults is 150 minutes of moderate-intensity activity per week, or 75
minutes of vigorous-intensity activity per week, or an equivalent
combination of moderate- and vigorous-intensity physical activity.
Recommendations for aerobic physical activity in the 2008 Guidelines
differ from those used in
Healthy People 2010 (HP2010) objectives, which call for adults
to engage in at least 30 minutes of moderate-intensity activity, 5 days
per week, or 20 minutes of vigorous-intensity activity, 3 days per week
2). To establish baseline data for the 2008 Guidelines and compare the percentage
of respondents who reported meeting these guidelines with the percentage who reported meeting HP2010 objectives,
CDC analyzed data from the 2007 Behavioral Risk Factor Surveillance System (BRFSS) survey. This report summarizes the results
of that analysis, which indicated that, overall, 64.5% of respondents in 2007 reported meeting the 2008 Guidelines, and
48.8% of the same respondents reported meeting HP2010 objectives. Public health officials should be aware that, when applied
to BRFSS data, the two sets of recommendations yield different results. Additional efforts are needed to further increase
BRFSS is a state-based, random-digit--dialed telephone survey of the noninstitutionalized U.S. civilian population aged
>18 years. Data for the 2007 BRFSS survey were collected from 430,912 respondents (median response rate: 50.6%;
median cooperation rate: 72.1%*) and reported by the 50 states, District of Columbia, Puerto Rico, and U.S. Virgin Islands.
Response rates were calculated using guidelines from the Council of American Survey and Research Organizations (CASRO). A total
of 31,805 respondents with missing physical activity data were excluded, resulting in a final sample of 399,107.
Since 2001, in alternate years, BRFSS surveys have included the
same questions regarding participation in moderate-intensity and
vigorous-intensity physical activities. In 2007, to assess
participation in moderate activities, respondents were asked, "When you
are not working, in a usual week, do you do moderate activities for at
least 10 minutes at a time, such as brisk walking, bicycling,
vacuuming, gardening, or anything else that causes some increase in
breathing or heart rate?" Respondents who answered "yes" were then
asked, "How many days per week do you do these moderate activities for
at least 10 minutes at a time?" Finally, they were asked, "On days when
you do moderate activities for at least 10 minutes at a time, how much
total time per day do you spend doing these activities?" To assess
participation in vigorous-intensity activities, respondents were asked,
"When you are not working, in a usual week, do you do vigorous
activities for at least 10 minutes at a time, such as running,
aerobics, heavy yard work, or anything else that causes large increases
in breathing or heart rate?" Respondents who answered "yes" were then
asked, "How many days per week do you do these vigorous activities for
at least 10 minutes at a time?" Finally, they were asked, "On days when
you do vigorous activities for at least 10 minutes at a time, how much
total time per day do you spend doing these activities?"
Using the 2008 Guidelines, respondents were classified as
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. Using the HP2010 objectives, respondents were
classified as physically active if they reported at least 30 minutes of
moderate activity, 5 or more days per week, or at least 20 minutes of
vigorous activity, 3 or more days per week.† Data were analyzed by
selected characteristics, age adjusted to the 2000 U.S. standard population, and weighted to provide overall estimates; 95%
confidence intervals were calculated. Statistically significant differences in prevalence were determined by t-test (p<0.05).
Using the 2008 Guidelines, 64.5% of U.S. adults were classified as physically active in 2007, including 68.9% of men and
60.4% of women (Table). By age group, the percentage classified as physically active ranged from 51.2%
years) to 74.0% (18--24 years). Among racial/ethnic populations,
prevalence was lower for non-Hispanic blacks (56.5%) than for
non-Hispanic whites (67.5%, p<0.01). By education level, prevalence
was lowest for persons with less than a high school diploma (52.2%) and
highest among college graduates (70.3%). By U.S. census region,§ prevalence was lowest among respondents in the South (62.3%)
and highest among those in the West (67.8%). A smaller percentage of persons classified as obese (57.1%) were physically active
than persons classified as overweight (67.3%, p<0.01) or of normal weight (68.8%,
Applying the HP2010 objectives to the same respondents, the percentage of U.S. adults overall in 2007 classified
as physically active was 48.8%, including 50.7% of men and 47.0% of women (Table). Greater prevalence estimates were
noted across all variables when comparing the 2008
with the HP2010 objectives; patterns by sex, age group,
race/ethnicity, education level, census region, and weight classification were similar.
Reported by: SA Carlson, MPH, JE Fulton, PhD, DA Galuska, PhD, J Kruger, PhD, Div of Nutrition, Physical Activity, and Obesity,
National Center for Chronic Disease Prevention and Health Promotion; F Lobelo, MD, FV Loustalot, PhD, EIS officers, CDC.
The findings in this report indicate that 64.5% of U.S.
adults reported meeting the minimum level of aerobic physical activity
in the 2008 Guidelines using BRFSS 2007 data. When HP2010 physical
activity objectives were assessed using the same respondents, 48.8%
reported meeting minimum levels of physical activity, a difference of
15.7 percentage points. Prevalence patterns by demographic variables
were consistent with those reported previously for physical activity (
3,4). Similar to findings in this report, a 2000 study noted a greater prevalence of physically active persons by using >150
minutes per week as the criteria, compared with six other criteria for moderate acttivity
The 2008 Guidelines reflect the most recent major scientific review of
the health benefits of physical activity. Officials at state and local
health departments and other agencies and organizations that promote
physical activity can utilize these evidence-based guidelines in
developing physical activity initiatives. Findings from this report can
serve as a baseline comparison with future estimates of physical
activity using survey data.
Analysis of the findings in this report identified two main
reasons why a higher proportion of respondents were classified as
physically active based on the 2008 Guidelines than based on the HP2010
objectives: 1) removal of the frequency and duration requirement (i.e.,
30 minutes of moderate activity, 5 days per week, or 20 minutes of
vigorous activity, 3 days per week) and 2) addition of the criteria
enabling respondents to meet the guidelines with a combination of
moderate and vigorous (multiplied by two) activity. The report from the
Physical Activity Guidelines Advisory Committee** emphasized total
volume of activity for health benefits, independent of frequency. As
explained in the 2008 Guidelines, existing scientific evidence cannot
determine whether the health benefits of 30 minutes of activity, 5 days
per week, are any different from the benefits of 50 minutes, 3 days per
week. As a result, the 2008 Guidelines allow a person to accumulate 150
minutes a week in various combinations (
1). Nonetheless, the 2008 Guidelines add that aerobic activity should be performed in periods of
at least 10 minutes, and preferably, those periods should be spread throughout the week.
The findings in this study are subject to at least three
limitations. First, BRFSS data are self-reported and subject to recall
and social-desirability bias; compared with accelerometer-measured
physical activity, higher levels of self-reported physical activity
were reported (
6). Second, BRFSS is a landline telephone survey
and excludes persons in households without telephone access or persons
who use only cellular telephones. Finally, the mean CASRO response rate
was 50.6%, and low response rates can result in response bias; however,
BRFSS estimates generally are comparable with estimates from surveys
based on face-to-face interviews. In addition, weighting adjustments
that account for sex, age group, and race/ethnicity attempt to minimize
nonresponse, noncoverage, and undercoverage (
Approximately one third of U.S. adults did not report meeting minimum levels of aerobic physical activity as defined by
the 2008 Guidelines. Minimum levels were analyzed for this report because they provided the most direct comparison
Healthy People 2010 objectives. However, more extensive health benefits can be attained by engaging in physical
activity beyond these levels (
1). Increasing physical activity among U.S. adults can be accomplished through informational,
behavioral, and environmental evidence-based approaches, such as those recommended in the
Guide to Community Preventive
evidence of increased physical activity has been documented for
communitywide campaigns, targeted health-behavior change programs,
school-based physical education, nonfamily social support, and
increased access to locations for physical activity combined with
information outreach activities. Evidence of increased physical
activity also has been documented for use of point-of-decision prompts
and for community-scale and street-scale urban design and land-use
policies and practices (
US Department of Health and Human Services. 2008 physical activity
guidelines for Americans. Hyattsville, MD: US Department of Health
and Human Services; 2008. Available at
US Department of Health and Human Services. Objectives 22-2 and
22-3. In: Healthy people 2010 (conference ed, in 2 vols). Washington,
DC: US Department of Health and Human Services; 2000. Available at http://www.healthypeople.gov.
Prevalence of physical activity, including lifestyle activities among
adults---United States, 1994--2004, MMWR 2003;52:764--9.
CDC. Prevalence of regular physical activity among adults---United States, 2001 and 2005, MMWR 2007;56:1209--12.
Brownson RC, Jones DA, Pratt M, Blanton C, Smith GW. Measuring
physical activity with the behavioral risk factor surveillance system.
Med Sci Sports Exerc 2000;32:1913--8.
Troiano RP, Berrigan D, Dodd KW, Masse LC, Tilert T, McDowell M.
Physical activity in the United States measured by accelerometer. Med
Sci Sports Exerc 2008;40:181--8.
Fahimi M, Link M, Schwartz D, Levy P, Mokdad A. Tracking chronic
disease and risk behavior prevalence as survey participation declines:
statistics from the Behavioral Risk Factor Surveillance System and
other national surveys. Prev Chronic Dis 2008;5(3). Available at http://www.cdc.gov/pcd/issues/2008/jul/07_0097.htm.
CDC. Comparability of data: BRFSS 2007. Atlanta, GA: US Depart-ment of Health and Human Services, CDC; 2007. Available at
Increasing physical activity: a report on recommendations of the Task
Force on Community Preventive Services. MMWR 2001;50(No. RR-18).
Heath GW, Brownson RC, Kruger J, Miles R, Powell KE, Ramsey LT,
Task Force on Community Preventive Services. The effectiveness of urban
design and land use and transport policies and practices to increase
physical activity: a systematic review. J Phys Act Health 2006;3(Suppl
* The response rate is the percentage of
persons who completed interviews among all eligible persons, including
those who were not successfully contacted. The cooperation rate is the
percentage of persons who completed interviews among all eligible
persons who were contacted.
† For example, both of the following
persons would be considered physically active under the 2008 Guidelines
but would not be considered physically active under HP2010 objectives:
a person who did moderate activity for 25 minutes, 7 days per week, and
a person who did vigorous activity for 40 minutes, 2 days per week.
West: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming;
Midwest: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin;
Northeast: Connecticut, Maine, Massachusetts, New
Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont; and
South: Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky,
Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Virginia, West Virginia, Tennessee, and Texas.
¶ Normal, overweight, and obese classifications are on the basis of body mass index, which is weight
(kg) / height (m)2. Normal: 18.5--24.9, overweight:
25.0--29.9, and obese:
** Available at http://www.health.gov/paguidelines/report.
†† Available at
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Date last reviewed: 12/3/2008