Questions for Lead Authors Debra L. Blackwell, Ph.D., Demographic Statistician, and Tainya C. Clarke, Ph.D., M.P.H., Health Statistician, of “State Variation in Meeting the 2008 Federal Guidelines for Both Aerobic and Muscle-strengthening Activities Through Leisure-time Physical Activity Among Adults Aged 18-64: United States, 2010-2015”
Q: Was there a result in your study that you hadn’t expected and that really surprised you?
DB/TC: The result that we found most surprising – and it really is quite striking – is the state-level variation in the percentages of adults who were meeting the federal physical activity guidelines through their leisure-time physical activity. We were also surprised that many of the states with the highest percentages of meeting the guidelines through leisure-time physical activity were “cold weather” states that get more snow during winter months. How are people in these states meeting these guidelines during the colder winter months? Are they participating in outdoor winter sports, do they exercise at indoor facilities, or some combination of outdoor and indoor activities? Unfortunately we can’t answer these questions with our data, but it would be interesting to know. In addition, previous research has generally shown higher rates of leisure-time physical activity for men than for women. This also includes studies that look at meeting the 2008 federal guidelines for aerobic and muscle-strengthening activities through leisure-time physical activity. While our current study also found that men were more likely than women to meet the guidelines through leisure-time physical activity, some states were exceptions – especially Colorado, but also in Massachusetts, Washington, New Hampshire, Utah, and Wyoming, where men and women had statistically comparable percentages.
Q: What would you say is the take-home message of this report?
DB/TC: This is a “good news” data report – for the most part. We think the real take-home message of this report is that, overall, American adults aged 18-64 are exceeding guideline targets for physical activity through their leisure-time physical activity. The Healthy People 2020 objective regarding physical activity specifies that 20.1% of all adults meet both aerobic and muscle-strengthening federal guidelines by 2020. We found that in 2010-2015, nearly 23% of adults aged 18-64 were accomplishing this through their leisure-time physical activity– a truly positive finding. But when we looked at differences by gender and work status, we found that among all women aged 18–64, 18.7% met the guidelines through their leisure-time physical activity, which is nearly two percentage points lower than the Healthy People target. While the average for working women (20.9%) was above the target, the average among all nonworking women was only 14.6%, almost six percentage points lower than the Healthy People 2020 target. Nonworking women in just five states—Colorado, Idaho, New Hampshire, Utah, and Washington—met the objective through their leisure-time physical activity. We should keep in mind though, that the National Health Interview Survey (NHIS) only collects information on leisure-time physical activity, so our study was not able to look at occupational physical activity.
Q: What made you decide to conduct this study on physical activity among Americans?
DB/TC: One motivation for conducting this study was that we wanted to look at state-by-state percentages. This new report is a continuation of a previous report (https://www.cdc.gov/nchs/data/nhsr/nhsr094.pdf) that looked at occupational differences among employed adults who met federal physical activity guidelines during their leisure-time physical activity. That report focused on individuals, not states, and excluded adults who were not working. While doing that analysis, we saw that there was considerable regional variation in the outcome. We wanted to expand that earlier research to include all adults in this same age group (working as well as nonworking), and to consider differences in meeting the guidelines by state because we had already seen this regional variation.
Q: What differences or similarities did you see between or among various demographic groups in this analysis?
DB/TC: We did observe some differences between men and women, as well as by work status, but we didn’t distinguish between many demographic groups since this was a state-level analysis. Men had higher percentages of meeting the guidelines through leisure-time physical activity than women overall — and within most, but not all, states. This was also true when we compared working and nonworking men and women overall and within most states.
Q: Why do you think there is such a vast difference among the states in the percentage of adults who meet the guidelines for physical activity through their leisure-time physical activity?
DB/TC: There are likely many factors that play a role in these state differences, as researchers are likely to suggest. We looked at just two: occupational distributions among working adults (and among working men and women), and at percentages of illness and disability among nonworking adults (and among nonworking men and women). States with higher percentages of professionals and managers — relative to production workers –generally had higher percentages of working adults meeting the federal guidelines for physical activity during their leisure time than states with more production workers and fewer professionals and managers. Similarly, states with higher percentages of nonworking adults in fair or poor health or with a disability had lower percentages of meeting the guidelines during their leisure time than states with fewer nonworking adults in fair or poor health or with a disability. Indeed, many factors are likely involved. And we only considered leisure-time physical activity in our study. Our survey doesn’t collect information on physical activity performed while at work or when commuting.
Q: What sort of trend data do you have on this topic that will help us see how physical activity for Americans has evolved over time?
DB/TC: There is some trend data available through various sources. The Centers for Disease Control and Prevention (CDC) has published several reports on this topic; the 2014 report is available at https://www.cdc.gov/physicalactivity/downloads/pa_state_indicator_report_2014.pdf, and a 2010 report is available at https://www.cdc.gov/physicalactivity/downloads/PA_State_Indicator_Report_2010.pdf. CDC also has mini-reports available for each state that take into account state-specific data; these are available at https://www.cdc.gov/physicalactivity/resources/state-action-guides.html.
Also, the National Center for Health Statistics (NCHS) reports Key Health Indicators based on the National Health Interview Survey (NHIS), including person-level estimates of adults aged 18 and over who meet the 2008 federal physical activity guidelines for both aerobic and muscle-strengthening activities during leisure-time physical activity. Please see tables 7.5 through 7.8 in https://www.cdc.gov/nchs/nhis/releases/released201806.htm#7A.
Q: Is this the most recent data you have on this topic?
DB/TC: While we do have newer data files, those data were not available when we were carrying out our analysis. So our current report is based on 2010-2015 National Health Interview Survey (NHIS) data. However, the most recent Key Health Indicators report at the website immediately above includes results from the 2016 and 2017 National Health Interview Survey.
Q: How many people were surveyed for this report?
DB/TC: The National Health Interview Survey, or NHIS, is a national, in-person survey conducted annually. Roughly 35,000 U.S. adults respond to the “Sample Adult” interview in any given survey year, and all of them are asked a series of questions about how often, how long, and how vigorously they spend leisure time doing exercise. This report looks at state-level variation in meeting the 2008 federal guidelines for physical activity through leisure-time physical activity among adults aged 18-64 using the 2010-2015 NHIS. The 2008 physical activity guidelines recommend muscle-strengthening activities at least twice weekly, with either moderate-intensity aerobic physical activity for at least 150 minutes per week, vigorous-intensity aerobic physical activity for at least 75 minutes per week, or an equivalent combination. For those of our readers interested in the specific sample sizes used in this analysis, here are the numbers:
Sample adults aged 18-64 years who met the guidelines for both muscle-strengthening and aerobic activities through leisure physical activity (n = 32,942) are the focus of the study. Sample adults meeting only one guideline (n = 48,810) or neither guideline (n = 70,402) are not shown separately, but are included in the denominators. Percentage estimates are based on pooled data from the 2010–2015 NHIS for all 50 states and the District of Columbia.