Wednesday, August 25, 2010

What About Running To Catch The Bus?

A study entitled The Effect of Light Rail Transit on Body Mass Index and Physical Activity was published in the August 2010 issue of the American Journal of Preventive Medicine. Apparently using light rail transit can help keep a few pounds off.

The implied average loss of 6.45 lbs induced by LRT use may be plausible if a person added walking 1 mile every workday to his or her daily routine. For a person weighing about 150 pounds, walking an extra 1 mile for 250 days/year would burn about 20,000 additional calories, or the equivalent of nearly 6 pounds. The average distance from home to the nearest station stop among LRT users was 1.5 miles, with bus stops located on average within 0.25 miles of their homes. The average estimated distance from a LRT station stop to a work address among LRT users was 0.35 miles. Using LRT could increase walking by approximately 1.2 miles a day, if one assumes that those using LRT to commute to work would walk to a bus stop to take to the local LRT station, and then walk from the destination stop to their work address.

The technical part:

Methods: Data were collected on individuals before (July 2006 –February 2007) and after (March 2008 –July 2008) completion of an LRT system in Charlotte NC. BMI, obesity, and physical activity levels were calculated for a comparison of these factors pre- and post-LRT construction.Apropensity score weighting approach adjusted for differences in baseline characteristics among LRT and non-LRT users. Data were analyzed in 2009.

Results: More-positive perceptions of one’s neighborhood at baseline were associated with a -0.36 (p<0.05) lower BMI; 15% lower odds (95% CI=0.77, 0.94) of obesity; 9% higher odds (95% CI=0.99, 1.20) of meeting weekly RPA through walking; and 11% higher odds (95% CI=1.01, 1.22) of meeting RPA levels of vigorous exercise. The use of LRT to commute to work was associated with an average -1.18 reduction in BMI (p<0.05) and an 81% reduced odds (95% CI=0.04, 0.92) of becoming obese over time.

Conclusions: The results of this study suggest that improving neighborhood environments and increasing the public’s use of LRT systems could provide improvements in health outcomes for millions of individuals.

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