Ironman is a long day. You will need to eat, and you will need to eat the right amount to finish strong. What you eat is personal, make wise choices. Here are some very simple thoughts about carbohydrates to consider before you begin.
Carbohydrates and Performance
- The body requires a continual intake of carbohydrates, which it converts to glucose, to feed the brain and fuel the working muscles. Any glucose not immediately used is converted to glycogen and stored in the liver or the muscles.
How much do you need?
- 3-4 grams per pound of body weight per day
- 3-4 grams is adequate for sedentary individual, but increased levels are necessary for maintaining high levels of performance.
- There are no known essential carbohydrates. There are “essential” fatty acids and “essential” amino acids (from protein).
Simple vs. Complex
- Carbohydrates come in two basic forms: complex and simple. Simple carbs are one, two, or at most three units of sugar linked together in single molecules. Complex carbs are hundreds or thousands of sugar units linked together in single molecules. Simple sugars are easily identified by their taste: sweet. Complex carbs, such as potatoes, are pleasant to the taste buds, but not sweet.
- It matters not if a carb is simple or complex. After digestion, it appears in the circulatory system in the simple form, as glucose, on its way to the cells where it is used for energy.
High Fiber Low Fiber
- There are two groups of complex carbs: high fiber and low fiber. High-fiber, complex carbs are not digestible, at least not by human beings, because we do not have the enzyme to do the job. Cows have that enzyme; that is why they can get calories out of grass, and we cannot. The main stuff in high-fiber, complex carbs which is indigestible by humans is called “cellulose.”
- High-fiber (high-cellulose) vegetable foods are the healthiest choices for human nutrition, and intake of these foods is associated with lowered incidences of hypertension, cancer, arthritis, diabetes, etc. Examples are lettuce and broccoli. Examples of low-fiber, complex carbs are banana, tomato, squash and all cereals and grains (therefore bread and pasta), potatoes and rice.
Carbohydrates and hydration.
- The fact that glycogen is transported by water in the mitochondria can not be ignored, every gram of glycogen used must be transported by water. If available stores of water are depleted through dehydration the transportation of glycogen is severely inhibited.
- Research has proven that stored glycogen is far more bio-available, and athletes with higher levels of stored glycogen have better sustained performances than those who supplement during exercise. The best time to replenish depleted stores are three hours prior to exercise.
What about Sports?
- Everyone has enough glycogen stored to produce appx. 2 hours of aerobic exercise. When levels are depleted the ability to exercise decreases.
- Internal stores can be extended by using oral carbohydrate supplements for events expected to last for over 2 hours.
- A well trained cyclist will need slightly more than 1 gram of carbohydrate per minute to sustain maximum performance. Tests have shown that drinking a liter of a 7% carbohydrate solution at the beginning and during an event improved performance by 2 %, over non supplementing groups.
- Swimming 1.25 hours X 784 calories per hour = 980
- Cycling 6 hrs. X 939 = 5,634
- Running 4 hrs. X 864 = 3,456
- BMR Body Weight x 24
- Total calories needed 11,924
Food as Fuel