.Although it's possible to approach an ultra from a standing start, most newcomers are marathon runners bitten by the long-distance bug. Training time Don't worry – you don't have to double your mileage if you double your race distance. The key is to emphasise
colds during the two-month pre-race period. (These months, January and February, are the peak cold/flu season in the USA.) Training more than 60 miles a week doubled the risk of infection. Also, in the week following the race, 13 per cent of marathon
