If you commute to work by car, and then sit in a chair while you work all day, you're pretty much begging for an early death. The effects of sitting too much are already well-documented, but new research shows that driving to work is so bad that even taking public transport makes you fitter, especially in later life.
The study, by researchers Ellen Flint and Steven Cummins, and published in the Lancet, studies the effects of commuting methods on the fitness of the middle-aged. The study takes its numbers from UK Biobank, a long-term study investigating genetic and environmental effects on disease and health. The sample size was a massive 73,000 men and 84,000 women, age 40 to 69.
The study found that taking public transport to work results in significantly lower Body Mass Index (or BMI) compared to going by car. The study also treated walking and cycling to work separately. In most other studies of this type, the two are combined which, say the authors, "perhaps understates the positive effects of cycling."
The most illustrative numbers are those showing how much thinner people are when they get even the small amount of exercise provided by taking the bus or train to the office. For men using only public transport, the BMI difference is 0.7. Combining public transport with other methods gets you a reduction of 1.0 in BMI.
That's a lot considering the difference between being obese and normal weight is only 5 points. Of course, it gets bigger when you look at more active forms of commuting, which also gives you an idea of how those BMI figures translate into actual weight:
For the average man in the sample [age 53 years; height 176.7cm (5'9.5"); weight 85.9kg (189 pounds)], cycling to work rather than driving was associated with a weight difference of 5kg or 11lbs.
"Many people live too far from their workplace for walking or cycling to be feasible, but even the incidental physical activity involved in public transport can have an important effect," Flint said in a press release.
In England, two thirds of adults do not meet recommended levels of physical activity. Ditching the car could make the crucial difference. In fact, for some people, the daily commute might be their only chance for exercise.
"Many people are not attracted to recreational sports or other leisure time physical activities, which are proven to benefit health," says Lars Bo Andersen of Sogndal and Fjordane University College in Norway, commenting on the study in the same journal. "Active transport might therefore be an important and easy choice to increase physical activity and the proportion of people achieving recommended levels of physical activity."
It seems a little sad that the only way many people can get fit is by taking the bus to work, but at least it's an easy regime to commit to. And you don't even need any special sports clothing.