Every athlete is looking for some way to perform better. In this search, many do not think about keeping their bodies properly hydrated. By being properly hydrated, an athlete will keep their performance levels up. The question is, however, what is the best way to keep one's self hydrated? Is water the best source or does your athletic type demand something more? Perhaps a sports drink packed with carbohydrates and electrolytes would be beneficial for your performance.
Dehydration causes fatigue and loss of coordination. Even the smallest amount (2% of body weight) of water loss can cause your performance to suffer. In order to avoid dehydration, you need to be consuming plenty of fluids before, during, and after workouts. By consuming 50-100 grams of carbohydrates per hour of exercise, the onset of fatigue can be delayed. Drinking alcohol or anything containing caffeine is not recommended, because they are diuretics, which cause dehydration from fluid loss in urine.
Fluid loss decreases blood plasma levels, which in turn decreases blood pressure. A decrease in blood pressure leads to a reduced amount of blood flowing to the muscles and skin leading to an increase in heart rate and body temperature. In an attempt to cool down, the body sweats. The electrolytes and water lost in sweat need to be replaced in order for performance not to decline.
An ideal sport drink will contain the proper ratio of electrolytes (sodium, potassium and chlorine). Electrolytes are responsible for maintaining the body's water balance and distribution, normal osmotic equilibrium, acid-base balance, and normal cardiac rhythm.
According to the RDA, the daily intake of sodium should be 2400 mg. We, on average, take in approximately 5 grams of sodium a day. It is for this reason that you should acquire a very small amount of sodium from your sports drink. The only reason for sodium in a sports drink is to balance out the electrolyte ratio.
Potassium is the most important component of the sports drink. Potassium converts glucose into glycogen, the storage form of glucose. Potassium is also essential for muscle contraction, hormone secretion and nerve transmission. Athletes use potassium at an accelerated rate, therefore requiring more potassium than the normal individual. Low potassium levels in the body can lead to a deficit in training progress. Since the major loss of potassium is through sweat and hemolysis (the lysis of red blood cells), it is important to replenish the supplies. A recommended intake of potassium is between 1,875mg and 5,625mg a day. An ideal amount of potassium in a 16oz sports drink is 200-250mg. Potassium should not be taken without carbohydrates or food. (Dr. Ann de Wees Allen)
Chlorine works in conjunction with sodium and potassium by controlling electrolyte and fluid balance. An acceptable level of chlorine in a 16oz sports drink is less than 100mg.
Fluid is absorbed in your small intestine. Glucose stimulates sodium uptake in the intestine triggering absorption, so fluids with a glucose/sodium ratio are most readily absorbed. It is for this reason that sports drinks containing this combination are effective as fluid replacement drinks. It has also been found that consuming fluids that are cold (less than 50 degrees F) are absorbed faster than fluids at room temperature. (Dr. Ann de Wees Allen)
An effective sports drink will contain a proper mixture of carbohydrates, making up 6-8% of the sports drink. Figuring out the percentage of carbohydrates in your sports drink is very simple. First take the amount of total carbohydrates in grams and divide it by the serving size in milliliters. Now, multiply your answer by 100 and you have the percentage of carbohydrates. With the right amount of sodium, this mixture helps replace fluids faster than water, improves performance, and helps insure optimal rehydration. A sports drink with less than 5% carbohydrates will not provide enough energy to enhance performance while more than 10% can lead to intestinal cramping, nausea and diarrhea.
When you consume carbohydrates that are high on the glycemic index, the body has a hard time regulating insulin in the body. As large amounts of simple sugars enter the blood stream, insulin is released causing a large uptake of sugar into the cells. As a result, a large amount of sugar is taken out of the blood leading to the feeling of fatigue. By consuming low glycemic foods, this can all be avoided. Low glycemic foods convert to sugar (glucose) at a slow rate allowing the body to adjust the sugar amounts in the blood. This in turn keeps the insulin levels in check and energy levels up for you.
Endurance athletes need to focus on the control and regulation of muscle glycogen synthesis and resynthesis. It is for this reason that a sports drink is ideal for the maintenance of their muscle glycogen during workouts/events. Bodybuilders, on the other hand, would only need high glycemic carbohydrates when their muscle glycogen is depleted. Not all bodybuilders will deplete their muscle glycogen stores and would store extra carbohydrates as fat if they were to try and replenish them. Sprinters and powerlifters have a similar problem. They only need to access energy quickly and for a short period of time. The only way muscle glycogen can become depleted is after 90 minutes of continuous exercise at more than 60% intensity and after 15 minutes of extremely intense exercise at 90% intensity. During all day events, it is important to stay hydrated and to occasionally supply the body with carbohydrates. By drinking a cup of sports drink every 20 minutes this can be achieved. It is only during this type of situation where sports drinks can be beneficial for bodybuilders, powerlifters and sprinters.
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References:
Drechsler, Arthur. The Weightlifting Encyclopedia. 1998
Hatfield, Frederick. Fitness: The Complete Guide. 7th Edition. 2001.
de Wees Allen, Dr. Ann. "What goes into a state-of-the-art sports drink?,"
www.energsportsdrink.com.
www.gssiweb.com - Gatorade Sports Sciences Institute
