Fuel your marathon training

Carbohydrate regime to meet training and racing demands

To meet the challenge of your marathon training are you fuelling up enough on carbohydrates? Your training diet is critical to help the body prepare for the race. The training diet should consist of approximately 60% of energy from carbohydrates, 20-30% from fat and 10-20% from protein. A regular high intake of carbohydrate allows you to get the most out of your training.

Carbohydrates are broken down in the body into glucose and used to fuel exercising muscles, the brain and other vital organs. Glucose is stored in the muscles and the liver as glycogen. Glycogen is broken down into glucose and used to fuel the early and later stages of exercise, and during high intensity activities.

If your regular diet (training diet) is low in carbohydrates and you are training for over 1 hour each day, you will slowly deplete your carbohydrate stores over time. You may feel fatigued and unable to train as hard. During a long run you could experience the phenomenon of “hitting the wall”, because you have run out of carbohydrate. Well stocked glycogen stores can help you train for longer periods, at a higher intensity, before you feel exhausted.

How much carbohydrate should I be eating?

Ideally, if training 5-7 hours per week, you should take approximately 5 to 6 grams of carbohydrate for every kilogram of body weight.

For example: a 60Kg runner training 6 hours per week will need:

= 60Kg x 5 to 60Kg x 6 = 300 to 360 grams carbohydrate per day.

To calculate your carbohydrate needs per day:

Body weight _____Kg

Multiply your body weight Kg ( ___Kg x 5) to ( ___Kg x 6) = ___ to ___g

What type of carbohydrate is the best?

Carbohydrates come in two forms, known as complex and simple carbohydrates. Ideally the diet should be made up of mainly complex carbohydrates because they tend to be more nutritious and they release energy slowly into the body. They contain B vitamins, which are important for energy production, iron, which is essential for making red blood cells to transport oxygen to cells, and fibre essential for a healthy gut. Simple carbohydrates tend to be found in more sugary products and are quickly released into the blood stream; they can be useful when the body needs a quick boost of glucose, just before or during exercise lasting longer than 60 minutes.

Do carbohydrates cause weight gain?

With the popularity of low carbohydrate diets, you may be concerned that carbohydrate will cause weight gain. It is the intake of excess calories rather than carbohydrate that leads to fat being stored in the body. Therefore, if you are concerned about your weight, try reducing the amount of fat in your diet.

Do I need Carbohydrate before I train?

To get the most out of your training make sure you have a carbohydrate rich meal 3-4 hours before exercising. This tops up your carbohydrate stores. If running for longer than 60 minutes you can take a snack within the hour before running. If exercising for longer than 60 minutes, you will need to take some food or drink containing carbohydrate. This can be provided by isotonic sports drinks which also help you re-hydrate, or try sports gels, energy bars, dried fruit, or bananas. The choice is yours; you will need to practice, as many runners can suffer from stomach upsets. Ideally aim for 30-60g of carbohydrate per hour; this will help you prepare for the big day.

What should I eat after training and when?

After training it is important to refuel on carbohydrate. You should ideally eat within the first two hours following training for the best benefits. You will need to plan ahead to make sure you have the food with you. Ideally you should take about 60-70g in the first 30 minutes, then every 2 hours until you manage your next carbohydrate rich meal. Remember to drink 500mls fluid immediately after the event and continue to re-hydrate. Ideally try taking some protein with carbohydrate to help recovery.

Fuelling your marathon training is critical to help you get the most out of your performance. This is the ideal time to figure out what works best for you. Make sure you practice with the gels etc before your race, when you find the right product and regime for you, stick with it!