Three fried-egg sandwiches with cheese, lettuce, tomatoes, fried onions, and mayonnaise on white bread; two cups of coffee; one five-egg omelet; one bowl of grits; three slices of French toast topped with powdered sugar and three chocolate-chip pancakes. This is just an example of the average breakfast Michael Phelps’ reportedly ate on his way to winning 8 gold medals at the 2008 Beijing Olympics. With a performance like that we have to think Team Phelps was doing everything right to help make him a champion. But the question is: Was diet one of those things?
There are athletes in every sport who both swear by their training diet, claiming that it gives them an edge over the competition and those who claim they only eat what feels good. Rafael Nadal, one of the all-time greatest tennis players, recently responded to fellow player Novak Djokovic who claimed that a gluten free diet and Chinese medicine propelled him to number one in the world (1,2). "Now it seems like the gluten-free diet is great," Nadal told reporters at the 2013 U.S. Open. "After three years or four years, we will find another thing that will be great, too. Then the gluten-free diet will not work anymore…I always had the theory that the most important thing is be happy."
While nobody would disagree with Nadal that being happy is important we cannot deny that certain foods will have an effect on the body regardless of personal preference. Gluten, for example, a composite protein found in the grains wheat, barley and rye, is made of gliadin and glutenin. The gliadin component of gluten has been found to directly interact with cells in the intestinal wall and stimulate the increased production of zonulin. This protein, found in all humans, helps open the permeability of the gut wall so the body can absorb large nutrients such as proteins and carbohydrates during digestion. Prolonged exposure to gluten prevents the body from closing the gut wall after digestion and protecting the bloodstream from toxins, microbes and undigested food. New research shows that everyone reacts with gluten in this way (3). While genetic tendencies play a significant factor in the severity of the reaction and whether or not someone may develop an autoimmune condition such as Celiac disease, Medical Director for The University of Maryland’s Center for Celiac Research, Alessio Fasano, says “No one can properly digest gluten. We do not have the enzymes to break it down. It all depends upon how well our intestinal walls close after we ingest it and how our immune system reacts to it.”
Understanding gluten is just one part of developing an effective yet healthy training diet and it becomes especially important when considering techniques such as carbohydrate loading. Most easily accessible carbohydrates come from processed wheat products. Not only does all that pasta potentially cause problems with gluten, you have to eat between 16-20 grams of carbs per pound of body weight just to meet the threshold for getting the body to store those carbs as glycogen in muscle tissue (4). You have to do this for approximately 3-4 days before the event and begin tapering off your exercise regimen. If you’re a woman, carbo-loading may not work for you at all! Most of the initial studies on carbo-loading were performed with men and updated studies show that a woman’s body will burn fat before carbohydrates during exercise with the elevated levels of estradiol (estrogen) that usually peak during ovulation (5). Carbo loading can get complicated!
For both genders, the digestion of carbohydrates and sugar is highly dependent on the amount and intensity of exercise being performed. The body doesn’t like large amounts of sugar in the bloodstream unless you are in the middle of an endurance event or sprinting to the finish line. When athletes consume a high carbohydrate diet they train the body to rely on a constant supply of sugar or use glycogen stores in muscle tissue rather than burning fats for energy (5). High carbohydrate diets are further complicated by the body’s insulin response if those carbs are not eaten directly prior to or during exercise.
Professional athletes across the board are recognizing the benefits of eating healthier and modifying their diets. While Novak Djokovic is gluten free, basketball players, Steve Nash and Grant Hill, credit the low carb, zero-gluten Paleo diet with their continued stamina on court. Football star, Aaron Rodgers, also subscribes to the Paleo philosophy and even Michael Phelps changed his diet on the way to becoming the most decorated Olympian ever at the London 2012 games saying “It’s like putting higher octane fuel in a car—I run better when I eat better.” Some diets are truly fads and some aren’t. Understanding how the body processes and uses food as fuel is the first step to building the perfect training diet.
1. Collins, L. (2013, September 2). The Third Man. Retrieved from www.newyorker.com: http://www.newyorker.com/reporting/2013/09/02/130902fa_fact_collins?currentPage=all
2. Drago, S. (2006). Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines. Scandinavian Journal of Gastroenterology (41), 408-419.
3. Shorten, K. (2013, September 28). Novak Djokovic’s credits his success to a diet of mostly warm foods. Retrieved from www.news.com.au: http://www.news.com.au/lifestyle/health/novak-djokovic8217s-credits-his-success-to-a-diet-of-mostly-warm-foods/story-fneuz9ev-1226728979095
4. Willoughby, J. W. (2006). Gender Differences in Carbohydrate Metabolism and Carbohydrate Loading. Journal of the International Society of Sports Nutrition (3), 28-30.
5. J. Lynne Walker, H. H. (2000). Dietary carbohydrate, muscle glycogen content, and endurance performance in well-trained women. Journal of Applied Physiology , 88 (6), 2151-2158.
6. Phinney, S. D. (2004). Ketogenic diets and physical performance. Nutrition & Metabolism (1), 1-2.