Carbohydrates are essential for peak athletic performance, as the body uses this nutrient more efficiently than fat or protein. When exercising the timing of carbohydrate intake is very important. Athletes should consume 1.0 to 4.0 g/kg of body weight one to four hours prior to exercise, focusing on longer-lasting sources of carbohydrate combined with a source of protein (e.g., peanut butter on whole grain bread).
Recommendations for carbohydrate intake are higher for endurance training and competition (7.0 to 10.0 g/kg/day) and high-intensity athletics (5.0 to 8.0 g/kg/day).
Sportsmen and women and anyone participating in exercise should ensure that they don’t exercise on an empty stomach, ie. going to the gym straight after work without a snack mid-afternoon.
Remember if you train correctly and don’t over exert yourself you are less likely to get injured. If you are running low on fuel when playing sport you are more likely to make errors that could result in injury.