Details
(With contributions from Debra Efroymson and Kristie Daniel)
In a recent Lancet paper Chi Pang Wen and colleagues demonstrate the benefits of even small amounts of exercise (eg 15 minutes per day) which is great news. But then they argued that "of the four domains of physical activity (work, transportation, household, and LTPA [Leisure Time Physical Activity])…LTPA is the most related with health benefits. Furthermore, only LTPA is effort-related and promotable.”
We disagreed and our letter to the editor in response was recently published. We wrote that "Transportation-related physical activity provides the opportunity for regular activity. ... Furthermore, transportation physical activity is promotable through changing the built environment so that, for example, walking and cycling to daily destinations could become not only safe but pleasant, and physical activity becomes incorporated into daily life. ... [W]e argue that transportation-related physical activity is the most appropriate for population-wide interventions."
As is normal the editors gave the authors of the article we were commenting on a chance to reply and they wrote "We wholeheartedly support walking or cycling to get to daily work destinations, if possible. For a small minority, such activity is achievable. However, when one stretches a three-block walk to a 13-block walk, transportation takes on the nature of leisure-time physical activity (LTPA), because it becomes a voluntary, optional effort, not a daily requirement. ... The tipping point for governments is the exercise culture of society and the prevalence of LTPA in these commuters. Only after a widespread need is shown by a large number of people already engaged in LTPA will governments or employers offer assistance for commute-related physical activity. Thus, an LTPA-motivated public is a prerequisite for promoting transportation-related intervention."
In other words, they are saying that not until a population is active through LTPA will a government be convinced that they should adjust infrastructure to support transportation-related physical activity to help people be more active. But if it is only in already fit cities that we can advocate for fitness-promoting environments, then there is no hope. Walkable and bikable environments should be developed as a proactive response to an increasingly overweight and unfit populace, not as a response to a fit population that is looking for even more activity.
If we make it easier and safer to walk and cycle in cities, people will walk and cycle more. Most current trips by walking and cycling, especially in low-income cities, are despite the poor environment, so improving the conditions would also disproportionately benefit the poor. And they've got the thing backwards: for a small minority, recreational physical activity is a likelihood. For most, physical activity needs to be part of one's daily routine, not an add-on.
There's another advantage to purposive physical activity: you don't need to be motivated each time. If it's your daily routine, if that's how you get to work/school/shops etc., then you just do it, without even thinking about it. THAT is the only solution for the majority.
A person living in Dhaka (or any poor city) is not walking 13 blocks as a "leisure-time" activity. In Dhaka, I would argue, people are walking because they are poor and have no other option. They may not have thought about the importance of physical activity in their entire lives. Our challenge in our Livable Cities program is to help make the walking and cycling commute an attractive option so that people continue to do that activity even if they have another choice.
In Canada, and probably other developed countries, the number one barrier people cite for not being active is not having enough time. Promoting leisure time physical activity requires you to do something different - exchange one unrelated activity for another (e.g., turn off the TV and go for a walk instead). For transportation-related physical activity, on the other hand, you are replacing one activity with a related activity (e.g. walk to the store, rather than drive). This directly addresses the issue of time because you are not being asked to do something extra in your day. You are doing what you would regularly do but doing it in a more healthy way.
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So how do we go about promoting these changes? That is an enormous challenge and is what our Livable Cities program is working on every day, but here is a nice video showing the Dutch experience, in terms of how they became pro-pedestrian and pro-cyclist. The Netherlands was going the way of the car - tearing down houses to build more highways etc... and then they decided to do something different. People may think that in the Netherlands people just naturally enjoy cycling without realizing the transformation the government had to make in cities to get the rates of cycling back up. It is just those types of changes to enhance purposive physical activity that our Liveable Cities program seeks to encourage in cities around the world.