Carbohydrate loading for triathletes

Nutrient loading is a concept where the athlete consumes more of a certain nutrient than her body can use in an effort to increase the stores of that nutrient for better performance later.  The most common nutrient an athlete loads would be carbohydrates.

During carbohydrate loading, the athlete reduces her training volume and increases her carbohydrate consumption in an effort to cause muscles to store higher amounts of glycogen.  This is generally done 3-4 days before an event.  The athlete will avoid fatty junk food and stick with low-fiber, high-glycemic load starchy foods (Hines, n.d.).  However, these foods are not only bad for regulating the blood sugars, they can lead to excess fat, high triglyceride levels, and liver damage (Hines, n.d).  These foods also tend to be missing several key vitamins and minerals the body needs in order for the Krebs cycle and the electron transport chain to extract glucose efficiently.

Carbohydrate loading is not necessary for shorter events lasting less than 90 minutes.  When the athlete is competing in a super-sprint and sprint triathlons, she needs to continue with her normal, well-rounded diet.  If she is competing in regular-length triathlons and has the opportunity to refuel during the event with sports drinks, sport beans, or goo, then she does not need to carbohydrate load to this extent.  She could increase her carbohydrate intake by 10-20% 3-4 days before the event to increase her glycogen stores, but she does not need to do more than that for optimum performance without weight gain.

Although carbohydrate loading has not been shown to provide a benefit to activities that last less than 90 minutes, it has been shown to postpone fatigue by up to 20% in endurance events lasting more than 90 minutes and to improve performance 2-3% (Hawley et al, 1997).  When an athlete is competing in an iron man triathlon, she would need to carbohydrate load as she would not have the opportunity to refuel enough for the effort expended during the event.  In order to carbohydrate load properly, though, she would need to include nutrient dense carbohydrates like fruit and whole grains (Hines, n.d.).  She would also need to avoid fruit juice, soda, sugary cereals, and candy as these are empty calorie foods with little nutritional value.  Carbohydrate loading is not an excuse to eat whatever she wants.

References:

Hawley, JA; Schabort, EJ; Noakes, TD; Dennis, SC (1997)  Carbohydrate-loading and exercise performance.  An Update.  Retrieved on April 13, 2012, from www.ukpmc.ac.us/abstract/MED/9291549/reload=0/sessionid=gRkUTTC;ZXP96Gxql7m6.6

Hines, Steve (n.d.)  Carb loading for Sport, Not for General Health.  Retrieved on April 13, 2012, from www.articlecity.com/articles/health/article-11913.shtml