When we recommend carbohydrate intake for the day, it is often expressed as grams per kg bodyweight. For example, for most sports this will be between 5 and 8 g/kg with values up to 12 g/kg on some days, in some sports. Protein intake is also expressed per kg body weight or per kg fat-free mass and this makes sense. However, when it comes to carbohydrate intake during exercise, recommendations are provided in grams per hour. A recent study challenged this view. Should we really change the recomm