One of the earliest was conducted in Great Britain by Dr. Jeremy Morris who studied the incidence of heart attacks in 31,000 transport workers. Morris found that bus conductors, who spend most of their day climbing up and down the stairs of double decker buses, averaging between 500 and 700 steps per day, had reduced incidences of heart disease than their bus-driving counterparts, who spent 90 percent of their day sitting down. Furthermore, when bus conductors did develop heart disease it came much later in life and was less likely to be fatal.
Dr. Morris took his research personally and seriously, engaging in regular exercise most days. He died a few months before his 100th birthday.
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