Sugar and Performance
If you are an endurance athlete, evidence suggests that eating some sugar (like energy bars, some types of candy bars, or sports drinks) 35 to 40 minutes before an event may provide energy (glucose) to your exercising muscles when your other energy stores have dropped to low levels. However, you should experiment with such strategies before competition because some people do not perform well after a blood glucose spike.

Caffeine and Performance
Caffeine acts as a stimulant on the central nervous system. It had been thought to boost endurance by stimulating a greater use of fat for energy, and thereby reserving glycogen in the muscles. Research, however, doesn't support that theory. When caffeine improves endurance, it does so by acting as a stimulant.

Caffeine can have serious side effects for some people. Those who are very sensitive to its effects may experience nausea, muscle tremors, and headaches. Too much caffeine is a diuretic, and can result in dehydration, which decreases performance.

Foods to Avoid Before Racing 
Any foods with a lot of fat can be very difficult and slow to digest and remain in the stomach a long time. They also will pull blood into the stomach to aid in digestion, which can cause cramping and discomfort. Meats, doughnuts, fries, potato chips, and candy bars should be avoided in a pre-exercise meal.

After Competition

Rehydrate Immediatly

The best rule of thumb here is to weigh yourself before you Race or Train and again After! Drink 20-24oz of water for each pound you lost.

Eating After Competition

This must be done within 2 hours of competition or training!  Eat a 4:1 Ratio of Carbohydrates and Protien. Example: 100 to 200 grams of Carbs with 25 to 50 Grams of Protien