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Sunday, January 27, 2008

Walk or Wait?

Many of you may know that since moving to Edmonton and living downtown, I now try to rely on the Edmonton Transit System for getting around town (i.e. when I cannot hitch a ride with someone).

So obviously the issue of whether to wait for the next bus (when I don't see one coming) or to try and walk to the next stop (so I don't have to stand still in the cold) is a big one.

Gratefully, I am not alone with this dilemma. As commented on recently in the Globe and Mail, US mathematicians have come up with the formula that allows you to calculate the odds of missing the next bus (by being caught between two stops as it whizzes by you) - the math is complex (taking into account distance to be travelled, distance between stops, frequency and speed of the bus, your own walking speed), but the bottom line is that unless you are traveling less than a Kilometer and the buses are around an hour apart, it is mathematically better to wait.

What the formula does not take into account is freezing your butt off by standing still. It also does not take into account any health benefits to be derived from walking to try and make it to the next stop and then breaking into a short run when you see the bus coming (my kind of exercise!).

Anyway, why even bring this up? Well, partly because I m a big believer in public transportation for its health benefits (and stress relief).

In a recent analysis by Edwards from City University of New York, Taking public transit is associated with walking 8.3 more minutes per day on average, or an additional 25.7-39.0 kcal. Based on the estimate that an increase in net expenditure of 100 kcal/day can stop the increase in obesity in 90% of the population. Additional walking associated with public transit could save $5500 per person in present value by reducing obesity-related medical costs (US). Savings in quality-adjusted life years could be even higher.

Similarly new studies from Sweden and Australia show that using public transportation or riding a bike to work is significantly associated with lower weight and better health. Oddly, in both studies the benefits were evident only in men.

I, for now, will of course continue using the ETS and sneaking a run to next base when I don't see a bus coming. I may be late for meetings but at least I'll be a little healthier.


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