- part of a series in our 2009 Flora London Marathon build-up. On Friday April 17, we'll be welcoming Olympic athlete - and Lucozade Sport Super Six mentor - Liz Yelling into the forums between 1pm and 2pm to answer your last-minute race-week questions

Nick Morgan is Lead Sport Scientist at Lucozade Sport.Read the whole forum debateQ. Is there any benefit in doing my long runs without taking on any products? Would they then have an 'extra-bonus' effect on race day? MaracuyaA. There is school

and to replace fluid you've lost trhough sweat. The guidelines are: 1g of carbohydate per kg of body weight as soon as possible after exercise, plus 10-20 g of protein. As for fluid, drink according to the amount of weight you've lost. Monitor your urine colour