Regarding your diet programme, the preparations for race day can start now. The good news is that you probably won't have to make drastic changes to your current eating habits; there is no need to buy expensive supplements or special foods.

Eat what suits you! Large doses of supplementary vitamins and minerals (such as iron) are not essential and produce no benefit if you are on a good mixed diet, but additional vitamin C in small doses is reasonable when fresh fruit and vegetables are in short supply.

Training helps you to sustain a high level of muscle glycogen if you eat a lot of carbohydrate. If you can, eat within two hours of your runs and the marathon. This helps replace the muscle glycogen quickly and speeds recovery.

Carbo loading

Do not change your normal diet drastically in the last week before the marathon, but decrease your intake of protein (meat) and increase your intake of carbohydrate (pasta, bread, potatoes, cereals, rice and sweet things), especially for the last three days when you should also be markedly reducing your training. This loads the muscle with glycogen. Unless you reduce your protein intake, you will not eat enough carbohydrate. (Not all runners are helped by first depleting carbohydrate with a long run and low carbo diet and then loading - this can make your muscles very heavy.)

Use this checklist to make sure you are giving yourself the right start:

You should aim to get around 60 per cent of all your daily calories from foods which are high in carbohydrate including bread, pasta, milk, potatoes, rice, beans, fruits and vegetables. Unlike protein and fat, carbohydrate is stored in your muscle so that it is readily available for energy when you are running.

Research shows that most athletes tend to perform better if they eat smaller, high carbohydrate meals more often rather than three square meals a day. Experiment to find an eating pattern that suits your running.

Some runners claim to perform perfectly well on an empty stomach, but it is fair to say that most of the scientific evidence is against them. Eating 2-4 hours before you exercise means that some of the gastric juices in your stomach will be absorbed, leaving you feeling less hungry when you set off.

ater is a vital part of your diet. It helps get rid of heat through the skin by sweating; it enables your body to get rid of waste products and toxins and also helps to transport glucose in the blood to your muscles so that you can exercise.

As a runner you need more than the eight glasses of water recommended for people who do no exercise. Try sipping on water throughout the day and eat plenty of high water-content foods such as tomatoes, soups and cucumber.

Research has shown that the ideal meal to eat on the morning of a race should be high in carbohydrate with a little low-fat protein to make it more digestible. Something like lightly scrambled egg on toast is ideal. But ultimately it is a matter of personal choice and you should be trying out as many pre-run meals as possible in training.

You can use isotonic sports drink which contains natural ingredients, mineral salts and carbohydrates to provide fluid and energy replacement during training. Isotonic contain particles of carbohydrate at the same concentration as your body's fluids so that they are absorbed into the bloodstream at the same rate as water. Hypotonic contain particles that are less concentrated than body fluid which means that they are more quickly absorbed by the body so that they can speed up the rehydration process.

A dehydrated runner will end up going nowhere fast. And it doesn't happen only on hot days - dehydration can be the cumulative effect of drinking too little.

A simple way to test if you are drinking enough is to check the colour of your urine. If it is bright yellow, it may have become concentrated with metabolic wastes because you aren't drinking enough.

A few days before the race and there is still plenty to do. You should concentrate on eating a high carbohydrate diet so that your muscles are constantly re-fuelled. And there are other rules too:

Don't try anything new: if you are handed free samples of snacks when you go to collect your number from the exhibition, save them until after the race. You may find that they cause gastro-intestinal upset.

Ideally you should eat your last big meal at lunch-time on the Saturday before the race. Have a light evening meal and a bed-time snack. Don't go to bed feeling hungry.

Race Morning:

In general a large meal takes around four hours to digest, a smaller meal up to two hours. Do not be tempted by a hotel breakfast or try anything new at this stage. Drink plenty of fluids in the 2-3 hours before you start and a small cup of water about ten minutes before the gun goes.

Drink to avoid:

Steer clear of cafferine-based drinks such as tea, coffee and cola as well as alcohol which can all promote dehydration.

Drinking in the race:

Rule number one is to drink before you are thirsty. The sensation of thirst is your body's way of telling you that it is already becoming dehydrated - the last thing you need during a race - and you could have lost around one per cent of your body weight by then. Start drinking fluids as early as you can and take a few sips every 15-20 minutes throughout the race. Remember that in hot and humid weather you will need to drink more.

What you eat and drink after the marathon influences how quickly you recover:

Recovery Fluids:

Try fresh fruit juice, which will supply carbohydrate, fluid and electrolytes or body salts - dilute with water if it tastes too acidic. Water will replace fluids as well as any commercial drink.

Eat within four hours:

As a guideline you should aim to eat 0.5 grams of carbohydrate for every pound of body weight 2-3 hours after you finish to top up your depleted glycogen stores.

Rest:

Yes, you deserve it! A hard race will deplete your body's stores of glycogen and your muscles will need at least two days rest coupled with lots of carbohydrate foods. This, of course, means you have plenty of time too.