FUELING YOUR BODY
by Kerrie Smith
Endurance athletes require all three forms of fuel the human body uses for energy: carbohydrate, protein, and fat. A major aspect for optimal performance is using the right fuel, at the right time, in the right amount. Like every aspect of success in endurance events, correct nutrition requires planning, practice, and training to obtain the benefits on race day.
As most athletes know, “carbs are king” when it comes to fueling the body for any endurance exercise. That does not mean that any carbohydrate at any time will keep you going. Carbohydrates can either help or hinder performance, depending on what kind you use, how much you use, and when you use them. For example, far too many misinformed athletes continue to use energy products loaded with simple sugars, or they use complex carbs, a better choice, but at the wrong time and in the wrong amounts. These practices actually impair, not help, your performance.
Most dietary sugars are simple molecules known as monosaccharides and disaccharides. The shorter the chain length a carbohydrate, the higher it will raise a chemical measure known as osmolality when dissolved. In solution, simple sugars can only attain about 6-8% concentration or they will sit undigested in your stomach, as the osmolality is incompatible with the digestive juices. Products containing simple sugars (typically sucrose, fructose, glucose, and/or dextrose) must be extremely dilute to match body fluid osmolality. This weak of a concentration presents a problem to athletes because it cannot provide sufficient calories (perhaps only 100/hour) to working muscles. To obtain enough calories from a weak 6-8% solution, an athlete would have to consume excess fluid, which certainly increases the risk of fluid intoxication. So using simple sugar-based “energy drinks” is not the best approach.
So, can we just mix a stronger concentration? No, this approach also fails. Making a double or triple strength mixture from a simple sugar based carbohydrate fuel won’t work because the concentration of that mixture will exceed 6-8%, far too concentrated to match body fluid osmolality. It will remain in the stomach until adequately diluted, which may cause significant stomach distress. Drinking more water to dilute your over-concentrated mix puts you back in the original state of increased risk of over-hydration and all the problems that creates, so that’s not a good option.
On the flip side, if you don’t drink more, your body will draw fluids and electrolytes from other areas that critically need these fluids and electrolytes (like blood and muscle) and divert them to the digestive system to deal with your over-concentrated simple sugar drink. This also will result in a variety of stomach-related issues, not to mention increased cramping potential and other performance-limiting issues. The simple fact is that using simple sugar-based products are not the better option for an endurance athlete!