Tips for Carbo-loading for Marathon runners

When training for endurance runs such as the Comrades Marathon it’s very important to make sure that not only your running strategy is on par, your nutrition is nearly as important and carbohydrate loading, commonly referred to as carbo-loading or carb-loading, is a strategy employed by many endurance athletes to maximize the storage of glycogen in the muscles.

What is carbo-loading?
Since the 1920’s, scientific studies have revealed the performance-enhancing properties of carbohydrate, especially before and during exercise. It has been shown that a relatively high carbohydrate intake delays the onset of fatigue during endurance events. Carbo-loading is a strategy involving changes to training and nutrition that can maximize muscle and liver glycogen (carbohydrate) stores prior to endurance competition. The extra supply of carbohydrate has been demonstrated to improve endurance exercise by allowing athletes to exercise at their optimal pace for a longer time. Anyone exercising for 90 minutes or longer is likely to benefit from carbo-loading.

Carbo-loading guidelines:

• Plan an exercise taper. Reduce your training load by 50 percent going into the last week before the event, and reduce it by another 50 percent over the last 3 days.
• Three days before the event, consume 7-10g of carbohydrate per kg body weight. For a 50kg athlete this means consuming 400-500g carbohydrate per day and for a 70kg athlete 560-700g carbohydrate per day (use the list below).
• Carbohydrate must form the bulk of all meals and snacks.
• Have smaller servings of protein foods at meals, so that you can leave more room for larger serves of carbohydrate foods.
• Sugar and sugary foods, including sports drinks, can provide a compact carbohydrate source.
• Be extra careful with your fat intake – save the calories for carbohydrates. Don’t get tricked with high-fat foods such as chocolate, ice-cream, rich desserts, and takeaways. These foods are a rich source of fat rather than carbohydrate and should be avoided.
• Be careful of getting carried away and don’t see this as an opportunity to ‘pig-out’.
• Over the final 24 hours you may wish to reduce your gastric contents so that you race feeling ‘light’. To do this, switch to lower fibre foods and make use of compact sugar foods. You may even like to use a liquid meal supplements or energy drinks to supply some of your carbohydrate needs.
• Drink plenty of fluids. You will need to be well-hydrated for a long event, especially in hot weather. It is a good idea to carry a water bottle around with you as a reminder.

List of foods containing 50g of carbohydrate:

• 3 slices of bread
• 10 crackers or 6 rice cakes
• 2 cups cereal or cooked porridge
• 3 weetbix
• 1 cup cooked rice/pasta/mieliemeal/couscous/samp
• 3 medium muffins
• 2-3 cereal bars
• 1 cup baked beans
• 3 cups peas/butternut/corn
• 3 medium potatoes/sweet potato or 1 cup mashed
• 3 medium pieces of fruit
• 3 tbsp raisins
• 500ml fruit juice
• 1L low-fat or skim milk
• 375ml low-fat flavoured drinking yoghurt
• 250ml fruit yoghurt
• 5 tbsp sugar
• 1 handful jelly babies
• 10 marshmallows
• 1-2 sports bars
• 500ml meal replacement drink (e.g Nutren Activ, Ensure)
• 800-1000ml sports drink
• 500ml cola or soft drink

Example meal plan for 70kg athlete aiming to carbo-load

• Breakfast: 3 cups cereal + 250ml low-fat milk
  1 medium banana
  250ml orange juice
• Snack: 1 medium muffin + jam
  500ml sports drink
• Lunch: 2 sandwiches (4 slices bread) + filling
  200ml low-fat drinking yoghurt
  340ml can soft drink
• Snack: banana smoothie (low-fat milk, banana, and honey)
  1 cereal bar
• Dinner: 2 cups pasta + 1 cup pasta sauce
  3 slices garlic bread
  2 glasses cordial
• Snack: 1 fruit bun + jam
  500ml sports drink
  (3380kcal, 590g carbohydrate, 125g protein, 60g fat)