You can warm up, stretch and train all you want, but you won't be able to run at your body's maximum speed without giving your muscles the food they need. Nutrition is just as important for a runner's performance as running shoes, and several specific foods categories can enhance your running speed and help you achieve your short- or long-distance running goals.
Low Glycemic Fruits
Fruits contain sugars and carbohydrates that can provide your body with the energy boost it needs to sustain a high speed of running. You can rank fruits by their glycemic index, which is the rate at which they're digested and raise your body's blood sugar levels. For the best sustainable energy while running, the authors of "Barefoot Running" recommend eating fruits with a low glycemic index. This prevents sharp spikes in blood sugar and the subsequent feeling of exhaustion. Such fruits include pears, peaches, apples and grapefruit.
If you plan on running at great speeds for a long time, such as during a marathon, you'll need to replenish the salt your body loses. Sports drinks are good for this, but the Colorado State University Extension notes that you can also make your own sports drink that's perfect for runners. Combine 7 tablespoons of sugar, 1/3 teaspoon of table salt and a quart of water. Shake the solution thoroughly to mix it all together. This provides a sodium level of 325 milligrams for every 1/2 liter.
Your body requires carbohydrates to replenish the glycogen stores in your muscles, which are quickly depleted when you run at high speeds. Without the proper level of carbohydrate intake, you can hit the proverbial wall when it comes to energy levels and sustaining your running speed. For optimum running speeds, get approximately 60 to 70 percent of your diet's calories from carbohydrates, recommends "The Competitive Runner's Handbook." Example sources of complex, healthy carbohydrates include beans and whole-grain products such as bread or pasta.
Caffeine works as a potent stimulant to help enhance your energy and give you that boost you may need to start a race off fast. Sources include caffeinated, gummy-type runner snacks, which also provide you with electrolytes and other nutrients that can help you during your run. Alternately, sip coffee or an energy drink an hour or two before your running competition.