Recent studies found that smiling at London bus drivers increases happiness. However, on the Number 24 bus to Hampstead Heath, Londoners are sceptical. “Bus drivers,” says. Liz Hands. a passenger. “are generally annoying me.”

It might seem improbable that a report on London’s buses could change behaviour. But it has happened before. London’s buses have an underappreciated role in the history, of medical science. In the 1940s, a single study of London’s transport workers transformed epidemiology(流行病学), medicine and the way we live now. Every time you go on a run, check your step-count, or take the stairs instead of the lift, you are following a path pioneered by the feet of the workers on London’s buses.

In the late 1940s, doctors were worried. Britain was suffering from an “epidemic” of heart disease and no one knew why. Various hypotheses(假设), such as stress, were suggested; but one thing that was not exercising researchers was exercise. The idea that health and exercise were linked “wasn’t the accepted fact that we know today”, says Nick Wareham, a professor of epidemiology at Cambridge University. Some even felt that “too much physical activity was a bad thing for your health”. Navvies, miners and farmers who did physical exercise also suffered from various diseases and died young.

At this time a young doctor called Jerry Morris started to suspect that the excess deaths from heart disease might be linked to occupation. He began studying the medical ‘records of 31, 000 London transport workers. His findings were breathtaking: conductors, who spent their time running up and down stairs, had an approximately 30% lower possibility of disease than drivers, who sat down all day. Exercise was keeping people alive.

Morris’s research was eventually published in 1953, just three years after a study by Richard Doll proving the link between smoking and lung cancer. Morris’s work had consequences both big and small. Morris now also took up exercise, handing his jacket to his daughter and just running. “People thought I was bananas.” Slowly, the rest of the world took off its jacket and followed.

Runners need to move 15 per cent faster on a treadmill (跑步机) to burn the same number of calories as jogging outdoors, research reveals. Researchers found running on treadmills significantly reduces the amount of oxygen joggers use. 【小题1】

Researchers from Milan University analysed the difference between running outdoors and on a treadmill in 15 physically fit males with an average age of 21. 【小题2】. And it was followed by 30 seconds of recovery for a total of 15 minutes both outdoors and on a treadmill. Oxygen use and exercise intensity were measured after both types of running.

The results revealed that when on a treadmill, runners use significantly lower amounts of oxygen, suggesting less effort is required. 【小题3】

【小题4】

A 15 per cent increase in running speed during a high intermittent (间歇的) intensity treadmill training session is the optimal solution to reach the same physiological responses as an outdoor training session.

【小题5】 But the previous research suggests the moving belt of a treadmill propels (推进) joggers forward, causing them to move faster. Exercising indoors also means gym-goers do not have to fight with steep hills or wind resistance. Michael Silverman, director of rehabilitation and wellness at Northern Westchester Hospital in New York, said, “Outdoors, you are changing surfaces constantly, fighting the wind, and making quick and sudden starts and stops, which will lead to increased caloric burn.”