The Science behind Carbo Loading

Glucose from carbohydrates are stored in limited amounts in your muscles and live as glycogen. It is glycogen that is the key ingredient that governs the length and intensity of your running. In general you muscles will become depleted of glycogen after around 90 minutes of exercise. The more glycogen you have stored the longer you can keep running for and at a higher intensity. As you run your glycogen stores are used up and your body will start to burn fat for energy. Carbo loading is therefore used to store extra glycogen that your muscles can tap into once the normal stores have been used up. The more carbohydrate stores you have the more energy you have the less chance you have of hitting that dreaded wall.

Before your marathon you need to increase your carbohydrates stores. You can’t fill your muscles with glycogen from just one meal. You need to start carbo-loading two or three days before your race. During these days you will be running none/or very few miles which will allow the glycogen to accumulate in your muscles.

Should I still eat protein when carbo loading?

In short, yes! Keeping protein in your diet will in fact give you an extra energy boost. Protein slows the digestion of carbohydrates and encourages the body to release it’s energy stores slowly rather than just giving a quick burst of energy (perfect for endurance events like marathons). Tuck into: beans, lentils, chicken breasts.

Things to eat when carbo-loading

Wholegrain Bread with Peanut Butter
Wholegrain Cereal/A bowl of porridge
Wholegrain Rice
Wholegrain Pasta
Sweet Potatoes

Tip: Make sure you don’t overload on carbohydrates, particularly the night before you race, as this can cause: belatedness, stomach problems and diarrhoea.

Want more?