Before long you'll be munching on carrot sticks instead of going out for ice cream. Drink plenty of water, even on days that you're not running. During your training period, you'll need to consume 3-4 liters of water a day at a minimum . Not exactly dinner table conversation, but the darker yellow your urine is, the more water you need to consume. It's a good idea to eat a small snack and have a glass of water about a half-hour before you run.
Carbohydrates are usually the best choice, with dairy being the worst.
This is because your body converts carbohydrates to energy faster than it does with other foods. Therefore, it is common for marathoners to eat a big bowl of pasta the night before the race. Quick note of caution - it is generally not a good idea to carbo load on a regular basis, particularly if you are concerned with weight maintenance . Like we said before, you should expect to spend about 26 weeks in training. The general idea is to slowly increase your distance, and then speed, over the 26-week period.