Athletes need carbs, but some carbs are better than others

A staple of most athletic diets, carbohydrates aren't all good or all bad. Some kinds promote health while others, when eaten often and in large quantities, actually increase the risk for chronic disease.

Regardless of what you've read or heard about the dangers of carbohydrates or about the supposed benefits of a low carbohydrate diet, carbohydrates are an important part of a healthy diet, especially for athletes.

Why you need carbohydrates
Carbohydrates provide the fuel needed for physical activity and proper functioning of various organs, such as the brain.
However, carbohydrates are not essential nutrients. It's possible for the body to obtain all its energy from protein and fats. But since protein and fats are vital for building body tissue, cells and enzymes, you'd be wise not to drain these
resources for energy production when carbohydrates are available to take the lead in that area.

Kinds of carbohydrates
Carbohydrates can be found in a wide array of foods and exist in a variety of forms. The most common and abundant are sugars, fibers and starches. The basic building block of a carbohydrate is a sugar molecule called a monosaccharide, a simple joining of carbon, hydrogen, and oxygen. Glucose, galactose and fructose (fruit sugar) are common food monosaccharides and are also often referred to as simple sugars.

When two monosaccharides merge, they create "disaccharides," such as sucrose and lactose. Sucrose is the basis of table sugar; lactose is the primary sugar found in dairy products. Starches and fibers are essentially chains of sugar molecules. Some contain hundreds of sugars. These are often referred to as complex carbohydrates.

Which ones are best?
At one time it all seemed so simple. Simple sugars were "bad" and complex carbohydrates were "good." Now we are urged to follow the lead of the USDA's Dietary Guidelines for Americans 2005 which forgoes the simple/complex distinction, instead recommending carbohydrates from fiber-rich foods and whole grains. Sugar's sour reputation is due to its association with diabetes and a poor buff-to-blubber ratio. It doesn't help that foods with little nutritional value like donuts, sodas and muffins happen to contain a fair amount of these simple carbohydrates. In general, a healthy diet should contain few processed foods that are abundant in sugar. However, there is no reason to avoid sugars completely. Fruit has its fair share of natural sugar but, because of its very high nutrient content, should be front-and-center in any diet.

There is also one circumstance in particular where the body responds favorably to simple carbohydrates. "After exercise, muscles rapidly take-up sugars to help replace energy (glycogen) stores," says registered dietitian Monique Ryan, author of Sports Nutrition for Endurance Athletes (Velo Press, 2007). After a good hard run or long pedal, consuming foods that contain carbohydrate sugars such as fruit, dairy and, yes, even the occasional treat like chocolate, can result in a more rapid recovery from physical exertion. "This makes post-workout the best time to satisfy a sweet tooth," Ryan said.

But, we should follow the USDA's advice on carbohydrates because "obtaining most of your daily (not post-workout) carbohydrates from unprocessed, high fiber, and nutrient dense choices improves the quality of your diet," she adds. Starches and fiber result in a slower rise in blood sugar that can help reduce the risk of diabetes, sagging energy levels and an expanding waistline.

Fructose gone bad
One final note: cheaper and sweeter than table sugar, high-fructose corn syrup can be found in a wide array of foods from ketchup to cereal to baby food. In recent years, research has found a link between this carbohydrate sweetener and diabetes and obesity. Steer clear of this nasty food ingredient by carefully reading food labels and focusing mostly on whole, unprocessed foods for the energy you need to make it to the finish line.

So, which foods are your best bets for top-notch carbs and which ones should be left on store shelves? Here's a list of healthy and not so healthy carbohydrate-containing fare:

Eat These
Vegetables
Fruits
Potatoes
Sweet potatoes
Whole grains (whole wheat pasta, whole wheat bread, whole grain cereals, brown rice, quinoa)
Low-fat dairy (yogurt, skim milk)
Beans
Dark chocolate

Not These
Pastries
Refined grains (white pasta, white bread, white rice)
Muffins
Donuts
Table sugar
Candy bars