If you're a regular runner or training for a marathon, then you are probably really pumped about your next run. However, every runner knows that every run isn't the same. Some days you feel light enough to lift off the ground. Other days you are slower and have trouble even meeting your minimum distance.

What causes the difference? A lot of it has to do with how you are fueling your body. That's right: food! It's not smart to exercise on an empty stomach, but eating the wrong way can really slow you down with cramps or headaches.

3 Hours Before

Now is the time to be focusing on carbs. No, we don't mean you should run down to the donut shop and have your fill. You need to focus on nutrition with a combination of complex and simple carbs. Whole grains and fruit or veggies are your best bet here.

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What to eat:

• Whole pasta with fresh tomato sauce
• Whole grain toast with a banana
• Oatmeal with peaches

Hint: Bananas are great idea here because they can give you a kick of potassium, which your body loses when you start to sweat.

You should avoid foods with only simple carbs and a high fat content.

What to Avoid:

• Donuts
• French Fries
• Soda

90 Minutes Before

Now it is a good idea to have a small snack, but be careful! You don't want to risk stomach cramps. Have small amounts of lean protein at this time.

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What to eat:

• A handful of nuts
• 1 grilled chicken breast
• Fat Free Milk or Yogurt
• Black beans

This is not the time to load up on carb dense foods. They can make you full and you'll actually feel them when running. Also avoid veggies because the added fiber may cause gastrointestinal issues during your run.

What to avoid:

• Salads
• Bread
• Fruit

30 Minutes Before

You'll want to make sure you're properly hydrated. At this point, food isn't a great idea, but a little caffeine to boost your performance might help.

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Drink:

• Water
• Green or Black Tea

Don't Drink:

• Soda
• Fruit Juice

As you can see, figuring out how to properly fuel your run isn't rocket science. Focus on the denser foods first and then work your way down through lean proteins, and into liquids. If you properly fuel your run, then you will be one step closer to that lighter than air feeling when your shoes first hit the pavement.

Remember that there is no magic formula for eating that is going to make you a good runner. That comes from practice. It also helps if you try to focus on healthy foods the rest of the time too, and not just right before your run.