Have you ever had or seen an athlete, who looks great in the heats and semis, but seems to be a shadow of himself in the finals? Most coaches fail to consider the most likely cause - low fuel.
Proper nutrition for athletic performance will comprise mainly two categories: nutrients that are building materials or nutrients that are fuel. Proteins, vitamins, minerals and essential fats are predominantly building materials. Carbohydrates are the fuel of choice for muscles, although proteins and fats may also be used for energy. During competition the athlete’s nutrition should comprise mainly nutrients that are fuel.
Carbohydrates that are ingested will be first broken down into glucose and then stored as glycogen in the muscles. Glycogen is the storage form of glucose. When muscles require energy to perform, it first taps into its glycogen stores, converting it back into glucose for energy. Once glycogen is depleted, the muscles will be able to convert proteins and fats into energy, but this process is very slow and muscle performance will suffer.
Aerobic vs. Anaerobic respiration
During aerobic exercise glucose and oxygen are turned into carbon dioxide and water releasing lots of energy, which fuels the muscles. If there is not enough oxygen, then the body shifts to anaerobic respiration. Glucose is then turned into lactic acid and releases far less energy. As lactic acid accumulates, it ultimately changes muscle pH which leads to the burning pain associated with muscle fatigue.
In designing an athlete’s nutrition for competition, the primary goal should be to achieve the highest possible level of muscle glycogen, prior to the competition. The level of glycogen in the muscles before you start exercise is the most important fuel determinant of performance. Glucose in the blood from carbohydrates just digested cannot be used by the muscles nearly as eff ectively as muscle glycogen formed from carbohydrates taken some hours previously.
Timing and type of carbs: simple vs. Complex carbs
The type of carbs ingested prior to competition is important. Simple carbs, when ingested, may cause fluctuations in your insulin levels which will hamper glycogen storage and hurt athletic performance. The timing of carbohydrates between competitions is also critical. Muscle glycogen synthesis is most rapid within the first 4 to 6 hours immediately after exercise or competition. This is the most critical time to resume muscle glycogen repletion. Both complex and simple carbs are important at this time as the body needs sugars quickly as well as over a sustained period. This is probably the only time that you can actually get away with simple sugars. The high demand for muscle glycogen right after exercise shunts the glucose directly into the muscles, so no insulin instability can occur.
For the week leading up to major competition it is important to start to load up on complex carbohydrates. Eat much more than normal, then taper off as you get close to the start of competition. The actual amount of carbohydrates needed depends on athlete individuality, body weight and exercise intensity and duration. To ensure optimal in-competition carbohydrate nutrition, carbs should be eaten in small meals throughout the day up to no more than 5 and no less than 3 hours before the start of exercise or competition. Complex carbs include sweet potatoes, beans and peas, yams, oats, brown rice, whole wheat bread. Simple carbs include white potatoes, carrots, honey, bananas, raisins, white flour spaghetti, white rice and white breads.