To run or not to run? That is the question: exercise and reduced risk of coronary heart disease

The recent National Fitness Survey has drawn attention to the population's low level of physical (aerobic) fitness and low level of activity. About one-third of middle-aged men and one-half of middle-aged women in England are unfit for continuous walking at a normal pace of about 3 mph. Similar fitness levels were shown for the Welsh population. At the same time, coronary heart disease (CHD) accounts for about 26% of deaths in England, and for 2.5% of the NHS expenditure. The suggestion that low fitness levels and low levels of physical activity are associated with a high incidence of CHD has been widely voiced since Morris's first study, and has more recently been the subject of editorials in the British Heart Journal and the BMJ.