Whether you run for fun or competition, what you eat and drink before, during, and after makes a difference. Night before: eat a large carb-loaded supper like spaghetti and salad. Day of: eat a medium-sized meal, like porridge, no later than 2 hours before the event. After: drink a cup of water for every 30 minutes you spent in the run. Consider a natural electrolyte replacement drink such as coconut water, if you run for longer than 90 minutes. Finally, a whole food source of protein and carbohydrate within 20 minutes of finishing will help restore your energy.