Researchers Confirm Link Between Active Commuting and Better Health

It makes intuitive sense that cycling and walking to work regularly
would help people stay healthy, but until now there’s only been
anecdotal evidence suggesting that places where
walking or cycling to work is common also have lower rates of obesity.

philly_cyclists.jpgBike traffic in Philadelphia. Photo: Kyle Gradinger, Bicycle Coalition of Greater Philadelphia

That changed in a significant way yesterday when the American Journal of Public Health published new findings
from researchers at Rutgers, Virginia Tech, and the Centers for Disease
Control and Prevention (CDC) that show a clear link between high levels
of walking and bicycling to work and positive health outcomes. The
study was led by John Pucher, an urban planning professor at Rutgers.

The researchers analyzed health and travel data from a variety of sources, including the U.S. Census’ American Community Survey, and the CDC’s Behavioral Risk Factor Surveillance System.

Among the 50 states, obesity rates range from 19 percent to 35
percent, while rates of active commuting vary from two to nine percent.

The
study found that there are significant connections between having a low
obesity rate and a high rate of walking or biking to work. The same is
true for diabetes. In statistical terms, about 30 percent of the
variation in obesity among states — and more than half of the
variation in diabetes — was linked to differences in walking and
cycling rates.

Among the 14 developed countries Pucher and
his colleagues compared, about half of the variation in obesity was
linked to differences in walking or cycling.

“It could have
been that people actually exercise less when they walk or bike to work
because they might forsake going to the gym,”
Pucher said. "We didn’t see that."

The nature of the analysis is such that it
doesn’t “prove” that walking or cycling to work will help any one
person lose weight, or that cycling or walking are the only factors
driving weight down in the countries, states, and cities where obesity is less prevalent. Other factors, including variations in the diet or
genetics of the people in particular areas, may also play a role and
weren’t included in the analysis.

Nonetheless, the findings complement a growing body of evidence that
Pucher and others have been compiling for the better part of a decade
that strongly suggests the way people travel has an impact on
their health and longevity. 

“Public health people
really get this now,” Pucher said. "Doctors are getting it more and
more. And, recently, transportation people, too. The big challenge is
that most Americans still don’t see the connection. A lot of people are
still waiting for a miracle pill."

For all Americans, the wait will surely be a costly one. The CDC recently highlighted numbers
showing that medical care associated with treating obesity costs Americans up to about
$147 billion each year.

  • garyg

    According to the abstract, the study found only a statistical association, not a causal relationship. As always with this kind of finding, correlation does not mean causation. The correlation may be explained entirely by selection effects. That is, obese people may tend to choose non-active modes of commuting more often than non-obese people.

  • tubob

    it seems pretty obvious that if you start biking or walking, you will lose weight. stupid sububanites

  • There are so many ways in which physical movement is essential to human health. Consider the lymphatic system, the Rodney Dangerfield of the body that gets no respect. Though most people don’t even know it exists, it is a key component of the immune system. Among other things, the body uses it to transport immune cells and antigen-presenting cells that stimulate the immune response. Because the lymphatic system doesn’t have a pump like the circulatory system does (the heart), it requires the contraction of skeletal muscles to push the lymph through the lymphatic vessel network. In short, if you want your immune system to work well, you have to move frequently.

    Even if a person is overweight, if they are physically active, they will be much, much healthier than a sedentary overweight person. Some studies show they might even be healthier than a sedentary normal weight person.

  • muenster

    As lead author of the AJPH article mentioned in the Streetblog article today on the link between active commuting and health, I would like to ask those criticizing the article to first read the article. It is available to the public on the AJPH website as well as via electronic journals. We dealt with almost all of the criticisms mentioned by the blog contributors so far. Instead of criticizing the AJPH article before even having read it, folks might want to first read the article. We specifically discuss all the limitations of our study and definitely do not claim that our results prove anything, only that they are consistent with the results of a growing body of evidence that walking and cycling on a daily basis provide valuable physical activity and promote health. Again, I would greatly appreciate it if critics would first take the time to read the full article. John Pucher

  • didrik

    If “muenster” is really Dr. Pucher, then bravo!

  • garyg

    As lead author of the AJPH article mentioned in the Streetblog article today on the link between active commuting and health, I would like to ask those criticizing the article to first read the article. It is available to the public on the AJPH website as well as via electronic journals.

    I went to your website and the article is only available for purchase. Perhaps you could provide a link an ungated copy.

    The abstract clearly states that the relationship you found was a statistical correlation. A statistical correlation alone is not evidence of causation. As I said, selection effects could account for the correlation without any causal link.

  • nanterking

    Gary,

    Correlation does not imply causation; that is true. But so what? Are you suggesting that increasing active modes of transportation does not reduce obesity rates? The causative link between activity and health and body weight *has* been established. There are possible confounders in this study, and you can’t tease out what is affecting the obesity rate more – the confounders or the activity level, but it’s indisputable that activity is improving the health of individuals partaking in it.

  • futurebird

    Why make it hard for people? The best changes are built in.

  • garyg

    Are you suggesting that increasing active modes of transportation does not reduce obesity rates?

    I’m not suggesting either that it does or that it doesn’t. I’m saying that a study that only found a statistical correlation between obesity and active commuting does help answer the question one way or the other. The correlation may simply be the result of non-obese people choosing active commuting more often than obese people.

  • Kenney

    Of course, one of the important things to take away from this is that, in those places where active transportation is high, OPTIONS for active transportation exist. It’s not just about getting healthier through not driving (which you could actually still do safely in many suburbs) its also about creating infrastructure that provides APPEALING alternatives to driving.

    Even further, think about what kinds of health amenities (good grocery stores and healthy dining-out options) are almost always available in places that have good transit, good sidewalks, and good architecture.

  • LMW

    improving our links and seeing the picture is key to healthy living, traveling and should assist our leaders which direction of guidance is need and since time is valuable, they will get that dollar flow needs attention and time links to those dollars. Health is costly, time helps. That would mean today.

    Change calls today.

  • Shawn

    I’ve used a bicycle as my sole transportation now for about 13 months. What a change in lifestyle! I have noticed health improvements, not to mention strong legs and a stronger mid section.

    unfortunately, my bliss may be coming to an end because of telecommuting. I presume this is even more energy efficent that biking, but it doesnt do much for your health.

    The office thinks they are being green by implementing a telecommuting policy, yet for my personal life, this will most likely mean less bike riding. Such a shame because commuting is the easiest way i’ve found to get daily exercise.

  • anon MD/MPH student

    hahah Gary. Ok its a statistical correlation and not a causal….

    but its a good thing we already *KNEW* that exercise has a lot of benefits, and that we already *KNEW* that exercise can help you lose weight…

    If its the other way around, obese people walk less, ok cool. You guys, Us guys, lets walk more!

    I don’t give a hoo-hah about not being able to PROVE that in a given country less walking caused obesity. I just want to do things that will decrease obesity. Because that’s what I care about. If all this research did was to show that Americans walk less, then I’m going to arm myself with that and say, you know what, other people walk on average a half hour more every day. That’s not that hard. You can do that too. In fact, go do it. Do it at 4 am so you can bird watch, or do it with your I pod drumming in your ears, or walk while you are on that lengthy phone call to whoever it is, but go do it.

    If I was wondering something about this article it was how they sampled the people they gave the pedometers to in each country. (Major city versus rural, etc) Because I am thinking, if it were me and I wanted to try this again 5 years from now, how WOULD I get a representation of America good enough to say “Americans” walk more/less/same as they did five years ago.

    I also wanted to find the article itself to read and I can’t, it would be nice if it was available for free 99 but it isn’t.

  • anon MD/MPH student

    mistake

    -carried to this comment stream via another link, got some wires crossed, please ignore the incongruities thanks

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