GETTY IMAGES The possibility of shaving a few seconds off a personal best, or running further than we ever thought we could, can lead us towards ever more inventive ways to train. But what
on to the water within our body. Every day we lose fluid by sweating, breathing and urinating. It's the sweating in particular that runners need to pay attention to because as soon as you start to run, you start to dehydrate. About 75 per cent of the energy you
