How important are nutrition supplements for runners? After all, it's entirely possible to eat badly and still go out and have a good run, so why should you concern yourself with good nutrition?

The answer is that to perform at your best, good nutrition is vital. Our bodies are designed to operate at peak efficiency - but only if we do the things that maintain that condition.

Supplements for your body

Exercising regularly, getting plenty of rest and sleep, and eating food that strengthens and nourishes you is essential. If you are regularly eating junk food, you are actually draining your body of energy, because it is hard work on the body to process all the extra sugar, salt and chemicals in junk food.

In fact, training hard and then eating junk makes as much sense as buying a Ferrari and putting industrial diesel in it!

So if you want to perform at your peak, what types of food do you need to eat? Rather than focusing on any one food, it's important to get a balance between carbohydrates, protein and fats. Traditionally, endurance athletes have eaten a diet that is around 75% carbs, 15% protein, and 10% fat, but athletes these days often eat a diet that is more like 40/30/30.

The key elements in a healthy diet are:

• Carbohydrates: There are lots of sources of carbs, not all good. Aim to get most of your carbs from fruit, vegetables, and whole grains

• Protein: Protein is essential for building and repairing muscles, so athletes - even runners - need plenty of protein. Look for lean sources such as fish, chicken, lean cuts of meat, and plant sources such as beans.

• Fats: Fat has earned an undeservedly bad reputation, being blamed for the obesity epidemic that is afflicting Britain, the USA and many other countries. However, fat is a vital part of the diet - good sources include fish, nuts, and oils such as olive oil.

In addition to eating the right types of food, you also need to drink plenty of water - especially before and after a run - and be sure to eat regularly. Experts recommend that you eat every two to three hours.