There’s truth in the old adage: “You are what you eat”. If you want to exercise and compete in top form, you have to eat well before, during and after exercise and racing. During exercise, muscles get fueled from nutrients (glucose) carried in blood. This fuel comes from either ingested carbohydrates or from stored glycogen (chains of glucose).
When the body can’t get enough energy from ingested carbohydrates, it starts to use muscle glycogen. In reality, the muscles’ ability – and need – to take up glucose from the blood exceeds the gastrointestinal system’s ability to deliver glucose to the blood. Therefore it’s important to make sure your glycogen stores are filled before exercise, and that you eat properly before, during and after exercise.
During long endurance workouts and races, your body burns between 500 and 1000 calories per hour, but it cannot digest more than 300 – 350 calories per hour.
It’s critical therefore to start each workout or race with a “full tank” from a proper pre-workout meal; and during the workout, to ingest up to 350 calories per hour in readily digestible form. The best form for this is sports drinks and carbohydrate gels since they are very quickly digested and absorbed into the bloodstream. If you ingest more than 350 calories per hour or if you eat slow-digesting foods (e.g. fats), the stomach will not empty completely and the food will remain in the gut, causing an upset stomach. Definitely not something you want during a race!
In addition to carbohydrates, protein has also been shown to enhance performance and promote recovery after exercise. Studies have shown that there is a definite benefit if you consume the proper balance of carbohydrates & proteins (4 to 1) immediately before, during and after exercise. Eat properly before and during races and you will see better race performance. Eat about 600 calories of carbohydrates and proteins (4 to 1) within 60 minutes of completing exercise and you’ll have faster muscle recovery.