Helping people maintain their health and fitness into old age is a public health priority. Appropriately, physical activity is a leading health indicator of the Healthy People 2010 (HP 2010) program (1) established by the U.S. Department of Health and Human Services (HHS). Steady increases in the number of older Americans (defined as those aged 50 years or older) (2) and in Americans' life expectancy (3) illustrate the importance of public health objectives related to the health and well-being of older adults. Physical activity is a critical part of a healthy lifestyle for older adults, and the benefits of regular physical activity are extensive. For example, regular physical activity by older adults has been shown to prevent falls and fall-related injuries (4), reduce existing functional limitations (5), and assist in reducing feelings of mild to moderate depression and anxiety (6).

This report focuses on physical activity recommendations addressed by the following five HP 2010 objectives concerning physical activity among the overall U.S. population: reducing the prevalence of no leisure-time aerobic activity to 20% (objective 22-1), increasing the prevalence of regular moderate- or vigorous-intensity aerobic activity to 50% (objective 22-2), increasing the prevalence of vigorous-intensity aerobic activity to 30% (objective 22-3), increasing the prevalence of muscular strengthening and endurance activity to 30% (objective 22-4), and increasing the prevalence of flexibility activity to 43% (objective 22-5). (Note that objective 22-2 was modified since HP 2010 was published in 2000: the most recent objectives can be found at http://wonder.cdc.gov/data2010/focus.htm.) We used data from the 2001 National Health Interview Survey (NHIS) (7) to evaluate how close various groups of older Americans (categorized by sex, race/ethnicity, education, and body mass index [BMI]) were to meeting these objectives in 2001.

Overall, the study sample consisted of 46.5% men and 53.5% women; 43.8% were aged 65 years or older, 80.6% were non-Hispanic white, 22.0% were college graduates, and 24.1% had a BMI ≥30.0 (Table 1).

Our results showed that, as of 2001, older Americans did not meet any of the five HP 2010 physical activity objectives for the general adult U.S. population (22-1 through 22-5). Although some subgroups were closer than others to reaching HP 2010 objective 22-2 (50% participation in regular leisure-time aerobic activity), the prevalence of regular aerobic activity among older Americans was generally low. We also found that the prevalence of strength training was substantially lower than the HP 2010 target of 30% and that only 8.2% of older Americans engaged in recommended levels of both regular aerobic activities and muscle-strengthening activities. These findings may aid efforts to meet national physical activity objectives by providing baseline estimates.

Other national surveys have shown that participation in physical activity decreases with age. For example, unadjusted findings from Healthy People DATA2010 indicate that from 1997 to 2004, Americans' rate of participation in all types of physical activity decreased with increasing age (9). Age-adjusted findings from the 2001 Behavioral Risk Factor Surveillance System (BRFSS) survey also showed that levels of both moderate and vigorous activity decreased with increasing age (10). A number of barriers can restrict physical activity as people age, including functional limitations (11), lack of access to activity programs (12), decreased confidence in one's ability to engage in physical activity (13), lack of knowledge about the benefits of physical activity (14), and not viewing exercise as an appropriate activity for one's age (15). Lack of physical activity among community-dwelling older adults has been associated with an increased risk for a decline in functional status (16), and physical activity has been shown to be health-enhancing even among those with functional limitations (11). One way to encourage older adults to become more physically activity is to increase their access to locations that offer physical activity and recreation opportunities. Settings that older adults regularly visit (such as senior centers, community centers, and recreational facilities) may have staff on site who could provide the encouragement and equipment necessary to help older adults incorporate physical activity into their daily lives.

The demographic patterns we found in rates of participation in various physical activities are not unique to Americans aged 50 or older: similar demographic patterns have been observed across the age spectrum (9). In addition, our results confirm previous findings that, as a group, older adults have a higher prevalence of no leisure-time aerobic activity than younger adults (17) and that the age-related difference is particularly high among those with less than a high school education (18,19). Predictably, we found that participation rates in all categories of activities that we examined were highest among those who had a college education. We also found substantial racial/ethnic differences in the prevalence of physical activity. Our finding that Hispanics were generally less likely to engage in leisure-time physical activity than were non-Hispanic whites is consistent with research findings in the general adult population (20–22). To eliminate this disparity between Hispanics and non-Hispanic whites, Poston and colleagues suggested that culturally appropriate interventions to increase physical activity among Hispanics need more than bilingual facilitators and materials (23). Analyses of activity levels by demographic subgroups (such as we did in this study) may be helpful in providing direction for additional research or in identifying appropriate target populations for interventions.

Our findings showed that only 8.2% of older Americans were engaging in recommended levels of both aerobic and muscle-strengthening activities. Strong evidence suggests that physical activity, especially activities that focus on muscle strengthening, can help older adults enjoy daily activities, reduce their risk of falling, and maintain an independent living status (24). A 2006 publication of the U.S. Department of Health and Human Services, A Healthier You, suggests that adults, regardless of age, can improve their overall health by engaging both in moderate- or vigorous-intensity aerobic activity and in strength training (25).

The findings of this analysis are subject to several limitations, including possible misclassification errors caused by survey participants overestimating their level of physical activity or by their possible confusion in being asked about their participation in vigorous-intensity activity before being asked about their participation in light- or moderate-intensity activity. Physical activity levels can also be tracked by using a number of commercial instruments that measure performance, such as changes in heart rate, time engaged in physical activity, or number of steps taken. Although these instruments can be used to validate self-reported physical activity and are the preferred gold standard in any study, their use is often not feasible or cost-effective in large population-based studies. However, the NHIS questions are similar to questions used in BRFSS surveys, which have been shown to have acceptable levels of validity (26,27). Other limitations of this study include limited opportunities for NHIS respondents to provide details about specific activities they engaged in (e.g., walking, running, or dancing for aerobic endurance activity), about their perceptions of barriers to and incentives for physical activity, or about where they performed any reported physical activity (e.g., community centers, fitness centers, senior centers); lack of information about the possible effect of language differences on the accuracy of people's reported behavior; and the study's reliance on data for only one year (2001).

The strengths of this study include its use of data drawn from a national survey of U.S. households whose questions allowed us to compare various physical activity rates among older Americans in 2001 with HP 2010 objectives. Our findings, which show that the proportion of sedentary older Americans remains high, can help define target populations for future physical activity interventions and may assist health education efforts to make older Americans more aware of the benefits of regular physical activity, including its potential to delay the progressive decline associated with aging. Only through such targeted promotion of physical activity can the national goals in HP 2010 be reached.