Active transportation is one of the single easiest ways to get more physical activity into your day. We all commute several times a day, and each of these trips represents an opportunity for physical activity through walking, cycling, or taking transit (which usually involves at least some walking) rather than driving. Active transportation may not sound like a tremendous way to reduce your health risk – I can understand if people doubt that a short walk or bike ride can have a long-term impact on health and longevity. To illustrate the benefits of even minor increases in physical activity I have created the following graph using data from a paper by Michael F. Leitzmann in the Archives of Internal Medicine, which followed 250 000 Americans aged 50-71 from 1995 until 2001. At baseline, all subjects completed a questionnaire detailing their level of physical activity, which the researchers used to then calculate the number of hours per week spent in moderate and vigorous physical activity, and to compare the risk of death associated with increasing amounts of activity.
This graph shows the relative risk of mortality across different levels of moderate physical activity (measured in hours/week). As you can see, individuals who are completely inactive have by far the highest risk of mortality, while those with the most physical activity have the lowest risk. But what is most interesting to me is that the greatest reduction in risk does not come from increasing physical activity among those who are already active. To be sure, moving from 1-3 hours of moderate activity per week to 4-7 hours of activity will reduce the relative risk of mortality. But, the greatest reduction in relative risk is seen when moving from complete inactivity to even minor levels of physical activity – less than one hour/week! That is less than 10 minutes/day! These results are only slightly attenuated by control for confounding factors including BMI, smoking status and family cancer history. These results are cross-sectional, so we can’t use them to infer causality (although I realize I am doing so to a degree). Similar results have been presented in numerous studies, and for just about every major cause of mortality, to the point that I believe even slight increases in physical activity among those who are currently inactive could have a profound public health impact.
All of this brings me to a strange article that I came across in The Telegraph yesterday. It reports on a new promotion by a brothel in Berlin (where prostitution is legal), which is now giving a €5 (~$7.50 USD) discount to patrons who commute by bike or public transit. To receive the discount, patrons merely provide proof of their transit fare, or show their bike helmet or lock. Thomas Goetz, the owner of the brothel, claims that the promotion has been a success for both the business and the community:
“We have around 3-5 new customers coming in daily to take advantage of the discount,” he said, adding the green rebate has helped alleviate traffic and parking congestion in the neighbourhood.
The ethics of prostitution are well outside the scope of this blog, so don’t take this to suggest that Obesity Panacea supports prostitution (legal or otherwise) in any way. But this anecdote does seem to suggest that people will use active transportation when incentives (even minor ones) are in place. This agrees with work by Ugo Lachapelle, which has shown that individuals who have access to a subsidized transit pass are more likely to meet daily physical activity recommendations than those who do note have access to such a pass (Mr Lachapelle discussed his work in an interview with Obesity Panacea earlier this year).
Let’s imagine that this promotion were being offered not by a brothel, but by a popular coffee chain like Tim Horton’s or Starbucks. I would wager that some individuals who are currently inactive would choose to walk or take the bus in order to get the discount. And over time, that could contribute to a reduction in health risk for those individuals. It’s not going to cure obesity, but keep in mind that the available cross-sectional evidence suggests that a relatively small increase in activity could dramatically reduce the risk of mortality in sedentary individuals.
What is also worth pointing out is that organizations that cater to individuals who commute by active transportation may also increase their business (just as Mr Goetz claims has happened for his operation). Many people like myself already commute by bike or by bus the majority of the time, and I would gladly patronize an establishment which provided me a discount as a result (I am obviously speaking here of businesses in general, as opposed to brothels).
Promotions aimed at increasing active transportation really are a win-win for all parties:
- People who use active transportation are likely to experience health benefits as a result
- Businesses which provide active transportation discounts are likely to attract customers who already commute actively
- Roads and parking lots around these establishments are likely to become less congested for those who choose to commute by car
- The environment (and everyone else) benefits from less greenhouse gas emissions
Active transportation is a great way to get more physical activity whether you are completely sedentary, or regularly active (don’t forget that there is almost always a benefit to increased activity, the benefit is just greatest for those who are inactive). It is pretty easy to work in 10 minutes of moderate activity each day, when you consider that those 10 minutes can include behaviors such as walking to the bus, or even just taking the stairs rather than the elevator at work. And if you are currently inactive, those 10 minutes could have a noticeable impact on your health and longevity (although it is worth emphasizing that 10 minutes/day is not the ideal amount of physical activity, it is still a step in the right direction). Let’s hope that more businesses and communities here in North America realize the value of incentives for active transportation.
Have a great weekend,
Leitzmann MF, Park Y, Blair A, Ballard-Barbash R, Mouw T, Hollenbeck AR, & Schatzkin A (2007). Physical activity recommendations and decreased risk of mortality. Archives of internal medicine, 167 (22), 2453-60 PMID: 18071167
This post originally appeared on Obesitypanacea.com on Oct 16, 2009.