Ever since Jim Fixx, the man credited with popularising jogging, collapsed with a fatal heart attack in 1984 after a run, the activity has been viewed with suspicion.
His 1977 Complete Book of Running, started a fitness revolution but when he died at just 52, critics claimed it as proof that running was harmful. In fact, Fixx had a family history of heart disease and he led an unhealthy lifestyle before taking up running at 35.
Jogging has its risks – like all activities. It has been linked with a series of medical scares – from jogger's nipple to premature wrinkles. Most are easily dealt with. Applying a plaster to the nipple before running prevents repeated rubbing. Premature wrinkles result when the jogger loses so much weight that they look haggard.
The most persistent criticism is: running damages the joints. But even on that score, medical opinion has changed.
Running is a high impact exercise but people who run regularly have less pain and less arthritis than non-runners when they get older. The benefit is best for moderate runners – up to 20 miles a week. Wearing the right pair of shoes is essential and running on softer surfaces reduces impact.
The highest profile cases are joggers who suffer heart attacks, but they remain rare. There have only been a handful of deaths among the hundreds of thousands of people who have run the London Marathon and they all had serious heart disease already.
The risk is greatest when people take up running. Doctors advise starting gently and working up gradually, to minimise damage.
But the truth is that you are more at risk of unexpected death if you don't run – or swim or cycle or exercise in some other way. The long term benefits of exercise on the heart are one of the few undisputed medical facts. There is another reason for running – it clears the head, stimulates the production of endorphins and lifts the mood – whether you are a high flying politician or an ordinary Joe.