Should you walk or get the bus? The healthiest option depends on which city you live in – but the more active option is almost always best.
We are often encouraged to drive less and walk more, but many cities like London have troubling air pollution statistics, which can leave people wondering which of their commuting options are really best for their health.
Now a study has weighed up these factors. Fortunately for those that prefer to be active, it has concluded that walking and cycling are almost always the better options for a person’s health.
This is the case in London and most other cities. The exceptions are some of the most polluted cities in the world – like Delhi in India, Karachi in Pakistan and Doha in Qatar.
But even in these cities, the damage caused by air pollution only outweighs the benefits of an active commute if a person is doing many hours of cycling a week, like a bicycle courier would.
Go ahead and exercise
Regular exercise is known to confer a host of health benefits, to the heart, lungs, muscles and bones, for instance, as well as warding off dementia. But many people can be put off exercising outside because of air pollution, which has been linked with heart disease and lung cancer – especially as breathing harder means more dirty air passes through your lungs.
Taking breathing rates into account, James Woodcock at the University of Cambridge and his team combined data on the effects of exercise on life expectancy with pollution readings from cities all over the world.
They found that even in Delhi – the most air-polluted city in the world – people would need to cycle for over five hours a week before the harm from the smog outweighs the health benefits of the physical activity.
For a city like London, which has much lower levels of pollutants, it is always better for your health to walk or cycle than take a more sedentary option like a bus, train or driving a car.
But Woodcock says we still need to take urgent steps to reduce pollution levels. “Pollution causes thousands of deaths a year. You’re breathing all this in whether you’re exercising or not,” he says.
If more people switch to walking or cycling instead of driving for the sake of their health, this will also bring down the amount of air pollution says Woodcock. “That’s a big win-win.”
Journal reference: Preventive Medicine, DOI: 10.1016/j.ypmed.2016.02.002