What you eat during the two weeks prior to the race can play just as big a role in your preparation as your training.
However, this does not mean that you should embark on a special diet: now is not the time to make sweeping changes.
Do not eat anything new.
Decrease your general calorie intake by 30% while increasing consumption of complex carbohydrates in your existing diet.
During this period, you will also be tapering your training also by 30%.
As you are burning fewer calories your calorie intake can also be reduced.
As with your training, running gear and sleeping habits, you should not change your diet just before a race.
If you have trained properly, maintained a healthy, balanced diet comprising fruits, vegetables, protein and complex carbohydrates, stick with what you know.
Your body may react badly to changes, which could spell disaster during the race for a number of reasons ranging from constipation to weight gain to feeling generally sick.
If you are racing abroad, remember that simple food is safest.
You may have trouble finding your normal fare, so it is a good idea to bring some whole meal bread, fruit, and vegetables, just in case these items are not readily available.
In a pinch, you can enjoy a simple meal in your hotel room.
Use caution when considering your racing diet, especially during the last three days before a marathon.
If you eat too little during this period, you may experience a profound energy drop around 20 miles and hit 'the wall' as runners call it.
That said, eating too much during the two-week tapering period may cause constipation or weight gain that you will have to carry during the race.
Three days before the race carb load, which involves consuming a larger percentage of your calories from carbohydrates than before.
They will top up glycogen stores without giving your body time to turn the extra calories into stored fat.