High Complex Carbohydrate Diet and Endurance

With so many becoming involved in long distance running, cycling and other endurance sports the relationship between diet and endurance is a growing debate:

Diet for Athletic Endurance:

The endurance factor of the muscles depends on the nutritive support for the muscle-more than anything else on the amount of glycogen that has been stored in the muscle and liver prior to the period of exercise. A person on a high complex carbohydrate diet stores far more glycogen in muscles than a person on either a mixed diet or a high fat diet. Therefore, endurance is greatly enhanced by a high by a diet high in complex carbohydrates.

For events that require heavy work for more than 90 minutes, a high complex carbohydrate diet eaten for two to three days before the event allows glycogen storage spaces to be filled. Long distance runners, cyclists, cross-country skiers, canoe racers, swimmers and soccer players report benefits from a precompetition diet where 70 percent of the calories comes from carbohydrates, primarily complex carbohydrates.

According to the Olympic Training Centre in Colorado Springs, USA, endurance athletes on a high complex carbohydrate diet can exercise longer than athletes eating a low-carbohydrate, high-fat, or high protein diet.
(see http://www.ext.colostate.edu/pubs/foodnut/09362.html)

Because the micro nutrients are not present in refined and simple carbohydrates (sugars and refined grain products like white flour) the ability of the body to properly process and utilize the energy in the food is compromised when these are used as the primary caloric intake. While the fuel is one important aspect, there are many other dynamics to strength and endurance that depend on a blood chemistry balance that can only be achieved by the consumption of unrefined basic foods (fruits, grains, nuts and vegetables). One example of this is the need for free flowing circulation. Simple carbohydrates (sugars) in high amounts thicken the blood, making circulation sluggish, especially at the capillary level where the blood interacts with the cells. This effect is magnified when combined with high levels of fat. The balanced use of whole foods is the safest and surest route to endurance strength. Also, the fibre found in natural foods is vital for a number of interactions, one of these being keeping the system free from toxins the can build up when the elimination becomes sluggish due to a fibre depleted diet. Fibre, along with adequate hydration, also helps balance and regulate the blood chemistry For optimum strength and endurance.

 While some simple carbohydrates (sugars) are needed to bring the blood sugar levels up quickly, the body cannot utilize too much at once.  The muscles rely on the glycogen stores, which are enhanced by the slow processing of the complex carbohydrates in unrefined foods.  Rather than drinking beverages artificially sweetened with processed sugars of any kind, juices consisting of 100% fruit or vegetable juices are superior and easier for the body to process.  Water remains the best beverage for hydration and cleansing under normal circumstances. 

One well studied example of the dietary factor of endurance is the Tarahumara tribe of Northwestern Mexico who are known for their ability to run longer distances than any other peoples on earth. They run distances up to 200 miles in the competitive sport of “kickball” races which often last several days. Their diet consists largely of unrefined beans and corn along with other vegetables. Their dietary intake is traditionally 80% complex carbohydrate, 10% protein and 10% fat and almost entirely plant based.
(see:http://www.ajcn.org/content/31/7/1131.full.pdf, http://www.lehigh.edu/~dmd1/art.html)