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A letter from an academic bemoans the dominance that the car has established over the pedestrian and cyclist. Wouldn’t it be an advantage, he asks, if we could persuade more people to cycle to work?

The debate about the extent to which global warming has been caused by fossil fuels, and the degree of change that gas-guzzling cars have made, is not one for this column. On the other hand, the advantages of steady daily exercise that makes someone breathless to the point at which conversation is difficult is of fundamental importance to cardiovascular and metabolic health.

The extent to which authorities equate exercise with organised sport, and the lack of interest that they show in cycling and brisk walking – the preferred forms of exercise from a medical standpoint – is disappointing because the former is potentially expensive and detrimental to people’s health.

Cycling is admirable exercise if pursued in areas unpolluted by heavy traffic fumes, and provided that helmets are worn. Although traffic fumes in heavily congested streets are not carcinogenic, in other ways they are as toxic to the lungs as cigarette smoke. A chest physician suggested to me some months ago that cycling through London was likely to be as damaging to the lungs as smoking several cigarettes.

I am convinced that people will start cycling only when bicycles are used for everyday transport rather than as exercise machines. Cycling in London and other large British cities, but not in mainland European towns, has been cornered by the nerdy cyclists who, wearing their distinctive uniform, weave in and out of traffic, ignore the lights, trespass on pavements and shout abuse at cars that impede their progress. Only when British commuters emulate their French, German and Scandinavian contemporaries and use bicycles to go about their business in their everyday clothes will more people take to cycling.

Incidentally, I made inquiries and found that our reader, the academic, cycles in his everyday clothes, doesn’t squeeze himself into Lycra and has impeccable road manners. The public road is not a private gym.

Similarly, doctors, health administrators and politicians must encourage people to walk briskly to work or wherever their destination may be, to ensure that they have 40 minutes or thereabouts of brisk exercise a day. Walkers should forget their T-shirts and shorts and forgo the rewards associated with showy marathons in favour of a daily walk in the park.

Arranging exercise for children is more complex, but it is unrealistic to expect children to play in the streets if there is a danger that they will be run over, or physically or verbally assaulted by a local gang.

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