We all store a certain amount of carbohydrate in our bodies,” says Cesca Baguley from Xendurance Europe (xendurance.eu). “But that will quickly become depleted as we run, so our fuel needs topping up on the go.”
Your body can consume about 60g-90g carbohydrates per hour. Any more and they will not be absorbed and you can then face gastrointestinal problems. Not fun anywhere, let alone half way through a marathon!