The new year is a time when many of us vow to head back to the gym. Moderate exercise not only helps us slim down and look better, it's also associated with all sorts of good health outcomes, from higher energy and productivity, better sleep and sex, and even greater longevity. In many cases, exercise may treat diseases as effectively as drugs, as one BMJ study recently showed.
Everyone knows it, but not everybody does it. Just a month after making those New Year's resolutions, 36 percent will already have given up, according to University of Scranton psychologist John Norcross.
And overall, American adults aren't nearly as fit as they should be, according to a report on aerobic and muscle-strengthening exercise released by the Centers for Disease Control and Prevention [see p. 326 of the PDF]. Drawing on data from the 2011 Behavioral Risk Factor Surveillance System survey, a nationwide telephone survey with more than 450,000 responses, the report looked at who met the 2008 Physical Activity Guidelines: two weekly sessions of muscle strengthening, and 150 minutes of moderate-intensity aerobic exercise (or 75 minutes of vigorous intensity).
Just 51.6 percent of U.S. adults met the aerobic activity standard and less than a third (29.3 percent) met the muscle-strengthening standard. Only roughly one in five Americans (20.6 percent) met both standards. (And, since the data is self-reported, there's a good chance these numbers might be inflated).
The overall numbers are concerning. And, they vary considerably by state.
To visualize this, my colleague Zara Matheson of the Martin Prosperity Institute mapped the variations for the percent of adults who reported meeting the guidelines for aerobic exercise, muscle-strengthening exercise, and both together. The first map, below, shows the overall pattern for aerobic exercise.
As you can see, participation in aerobic exercise is most prevalent along the West Coast, in the Rocky Mountain states and the northeast, and far less so in the middle and southern portions of the country.
Colorado tops the list among states, with 61.8 percent of adults meeting the standard for aerobic exercise; Oregon is second (61.1 percent), followed by Vermont (59.2 percent), Hawaii (58.5 percent) and California (58.2 percent). On the flip side, the lowest levels of participation in aerobic exercise are found in southern states – Tennessee (39 percent), Mississippi (40 percent), Louisiana (42 percent), Alabama (42.4 percent) and West Virginia (43 percent).
The second map shows the results for muscle-strengthening exercises.
The map shows a similar pattern, with higher participation in muscle-strengthening in the West, the Rocky Mountains, and northeast and lower levels in the interior and the South. D.C. now tops the list (36.1 percent – though as always, D.C.'s presence on state lists is complicated by being a 100 percent urban area).
Ranking the states, Colorado is in second (35.6 percent), followed by Alaska (33.8 percent), Virginia (33.4 percent) and Arizona (32.5 percent). Conversely, West Virginia (20.2 percent), Tennessee (20.6 percent), Oklahoma (23.8 percent), Mississippi (23.9 percent) and Louisiana (23.9 percent) have the lowest levels of participation.
And finally the third map, below, charts the states whose residents score highest on both types of exercise.
Again, the highest levels are in the West and Rocky Mountain states and the northeast, with the lowest levels concentrated in the interior and South. Colorado is again first, followed by D.C. (26.3 percent), Alaska (25 percent), Arizona (24.2 percent), Hawaii (23.7 percent) and California (23.7 percent). On the flip side, West Virginia (12.7 percent), Tennessee (12.7 percent), Mississippi (14.2 percent), Alabama (15 percent) and Louisiana (15.5 percent) have the lowest levels of participation.
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What factors lie behind these geographical patterns?
To get at this, my MPI colleague Charlotta Mellander ran a basic correlation analysis on participation in exercise and a number of key socioeconomic, demographic and health factors. I report the correlations for combined aerobic and muscle-strengthening, but the pattern for the two types of exercise individually is similar. As always, I note that correlation does not equal causation.
As the maps suggest, both forms of exercise are highly correlated with one another. States where people participate more in aerobic exercise also have higher levels of muscle strengthening (the correlation between the two is .81).
Also not surprisingly, states where people exercise more also have significantly lower levels of obesity and smoking, two known causes of preventable deaths. Mellander found substantial negative associations between exercise levels and obesity (-.80) and smoking (-.63).
You might think people would exercise more in warmer, sunnier states. But that’s not the case. She found a negative correlation (-.38) between yearly average temperature and exercise across the 50 states.
Exercise levels also correspond to wealth and affluence, with substantial positive correlations to both income (.65) and wages (.64). States where people exercise more are also more highly educated, with a significant correlation (.68) to the share of adults who are college graduates. And exercise levels are higher in states with more post-industrial economies, as participation was highly positively correlated with the share of knowledge, professional and creative workers (.51) and negatively correlated with the share of blue-collar workers (-.65).
Fitness participation also tracks the nation's red/blue divide, being positively associated with the share of Obama voters (.51) and negatively associated with Romney voters (-.53). Exercise also hews closely to America’s religious divide. People in more religious states exercise less (the correlation between religiosity and exercise is -.69).
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Writing in The Atlantic a couple of years ago, I noted that the physical fitness of our cities and metro areas is geographically spiky, and that "healthy or unhealthy lifestyles... are inextricably tied up with the nature and structure of our culture and society."
The fault lines of our economic geography shape our destiny: income, education, and social class influence everything from partisan preference to health. Exercise, it seems, is no exception.
"America's increasingly uneven geography of fitness," I concluded, "is perhaps the most visible symbol of its fundamental economic and class divide." This more recent report provides further evidence for this unhappy state of affairs.
All maps by MPI's Zara Matheson based upon CDC report data. Top image courtesy Shutterstock.com/Skydive Erick.