Does riding a bike have a similar effect as meditating? Can bicycles be used to treat attention deficit hyperactivity disorder (ADHD) or Parkinson's disease? Can biking make us smarter? These are among the questions scientists are aiming to answer in an effort the grasp the psychological benefits of biking and exercise.

"Several studies have shown that exercises including cycling make us smarter," says Usborne. "Danish scientists who set out to measure the benefits of breakfast and lunch among children found diet helped but that the way pupils travelled to school was far more significant. Those who cycled or walked performed better in tests than those who had travelled by car or public transport, the scientists reported last month."

"Cycling has even been shown to change the structure of the brain. In 2003, Dr Jay Alberts, a neuroscientist at the Cleveland Clinic Lerner Research Institute in Ohio, rode a tandem bicycle across the state with a friend who has Parkinson's to raise awareness of the disease. To the surprise of both riders, the patient showed significant improvements."

While the science on the psychological impact of cycling is far from complete, "[t]he apparent mindlessness of pedalling can not only make us happier...but also leave room for other thoughts, from the banal to the profound," argues Usborne. "On the seat of my bike, I've made life decisions, 'written' passages of articles, and reflected usefully on emotional troubles. Of his theory of relativity, meanwhile, Albert Einstein is supposed to have said: 'I thought of it while riding my bicycle.'"