There were quite a few interesting replies to my tweets (@cyclingscience1) about recent papers that had been published in science journals and they have prompted me to contact a scientist involved in the original research.
The paper that had got the most interest was about the fitness benefits for children who cycle to school. The original research was done by a team from the University of Granada, Spain and published in Preventive Medicine, August 2012.
In summary, it said that children who cycled to school in Sweden over a six year period were improved their fitness 20% more than those who walked. That’s understandable, particularly if they had hills on their routes.
The strangest fact, though, was that the cyclists were found to improve their fitness by only 13% more than children who went to school by “passive” modes (car, train, tram or bus) over six years.
So it would suggest that children who go to school in a car or other vehicle get 7% fitter than walkers.
Surely that can’t be right? Why should active walkers be less fit than the apparently inactive “passive” pupils?
A few ideas about this were mooted via tweets. Maybe children who travelled by car came from wealthier homes and so had healthier diets than the walkers? Maybe the walkers started out fitter at the beginning of the six year period and so couldn’t improve as much as “passive” children?
The best way to sort it out was to ask the paper’s lead author, Professor Palma Chillón Garzón at the unversity’s Department of Physical Education and Sport. Here’s his reply:
“It is correct that fitness increased lightly more among those who used passive modes than those who walked, but these differences are very small (fitness increased 1,289 in passive and 1,235 in walkers, and 1,488 in bikers).” [We assume a baseline fitness index of 1000 at the start of the six year period.]
So how does he explain the apparent fitness advantages of passive travel relative to walking?
“… there other variables that affect fitness like genetics, physical activity in the leisure time…etc. For this reason, maybe young people who use passive modes to school might practice more physical activity in the leisure time than those who walked to school.”
The upshot is that the research set out to quantify the fitness improvements, not to explain the reasons. That’s another task. Who’s going to do it?
In the meantime, the more children who cycle to school, the better. Unfortunately, parents from different parts of the UK tweeted that their children’s schools didn’t allow them to cycle, even when staff are themselves cyclists.
Among the replies to the original tweet, one question remains unanswered: what proportion of children live within cycling distance of schools in southwest Pittsburgh? Any answers? Has that figure been worked out for any school? Cycle campaigners would find it very useful.