There are many different substances that an athlete might use as an ergogenic or performance enhancement aid. Ergogenic means "having the ability to increase work, especially to increase the potential for work."59 The substances can be as simple as a type of food, a sports drink, or a natural substance taken to enhance energy; or as sophisticated as a prescription drug that can cause physiological changes. One thing the athletic trainer should bear in mind is that the use of ergogenic substances will mainly augment the ability of the athlete to continue in an activity longer or respond a little more quickly to a stimulus. In the majority of instances, performance-enhancing substances do not provide the athlete with an increased skill level (e.g., an increased ability to make free throws in a basketball game).
Some ergogenic substances are illegal and have a higher potential for being life threatening. Many other substances are readily available to the athlete and are relatively safe. In this section, we discuss those substances that are either marketed as ergogenic or have been scientifically studied to determine their effectiveness in assisting an athlete to perform at a higher level. Substances considered ergogenic include sports drinks; dietary techniques; vitamin, mineral, and amino acid supplements; and prescription drugs.
Over the years many companies have aired television commercials, or used print media along with team sponsorships, to promote their specific sports drink as being the most efficient at replacing lost water and electrolytes in the exercising athlete. The amount spent on advertising indicates that this is a very lucrative market for the sports drink companies. If one looks closely at the published literature over the last 10 years, all of the major sports drink companies have, at some time, laid claim to the title of being the best at rehydration and replacing electrolytes lost during exercise.
The first widely available commercial sports drink was Gatorade, developed in a University of Florida exercise physiology laboratory to help the college's football players (nicknamed the Gators) to rehydrate during the hot and humid days of summer and early fall. Whether or not it really helped the Gators with rehydration, they subsequently had a winning season and thus attributed their success to this new drink. More and more teams wanted the drink, and the increasing demand for it initiated thoughts of a commercial enterprise. Gatorade was first marketed as a way to help athletes compete longer at a higher level even in the heat and humidity. We are all familiar with the financial success of Gatorade. Now many other companies have cashed in on the growing market with their own sports drink formulations that they claim work better than the rest.
There have been numerous research projects to determine the rate of absorption of fluid and electrolytes from sports drinks. Most, if not all, of the manufacturers in this area are now using similar carbohydrate types and concentrations in their products because researchers have determined the levels of both that are most efficiently absorbed by the intestinal tract. The slight variations in carbohydrate type and concentration that do exist are used by sports drink manufacturers as marketing tools. For example, Gatorade is formulated with 5 percent carbohydrate and POWERade contains 9 percent.9
Possibly the most important variable influencing an athlete's consumption of a sports drink is the taste. If an athlete likes the taste of the drink, he or she will consume more of the drink and therefore rehydrate faster. The actual benefit of a sports drink as a performance enhancement product has been shown to be effective in some studies involving prolonged exercise, but other published research does not provide the same conclusion.9 However, as long as there is a profitable market for sports drinks, their effectiveness will continue to be argued.
A new entry into the sports drink market in recent years is the category of drinks marketed as "energy boosters." These drinks are typically made with high levels of caffeine and other stimulating natural substances. The excessive amounts of caffeine in some of these drinks can cause upset stomach, produce diuretic effects, act as a laxative, and produce levels of caffeine in the urine large enough to be detected or questioned in a drug test. Energy drinks with added herbal or natural substances can present the same types of problems regarding purity, toxicity, contamination, and drug interaction as were discussed earlier in this chapter. Table 13–3 lists the ingredients of some popular energy drinks.
Table 13–3Energy, Carbohydrate, and Additional Ingredients Found in Selected Energy Drinks ||Download (.pdf) Table 13–3 Energy, Carbohydrate, and Additional Ingredients Found in Selected Energy Drinks
|Product ||Energy (kcal/8 oz) ||Carbohydrate (g/8 oz) ||Additional Ingredients |
|Arizona Extreme Energy Shotb ||124 ||32 ||Caffeine, taurine, ribose, ginseng, carnitine, guarana, inositol, vitamins |
|Arizona Rx Energyb ||120 ||31 ||Caffeine, ginseng, Schizandrae, vitamins |
|Battery Energy Drinkb ||114 ||27 ||Caffeine, guarana |
|Bawls Guaranab ||96 ||27 ||Caffeine, guarana |
|Dynamite Energy Drinkb ||95 ||25 ||Caffeine, taurine, inositol, vitamins |
|Effervescent Glutamine Recovery Drinkh ||24 ||0.8 ||Glutamine, electrolytes |
|Gatorade Energy Drinkk ||203 ||52 ||Vitamins |
|G3 Enduranced ||90 ||24 ||Galactose, protein, chromium, green tea, ginseng, vitamins, minerals |
|G4 Recoveryd ||110 ||27 ||Ginseng, galactose, green tea, vitamins, protein |
|Hansen's Energyb ||107 ||31 ||Taurine, ginseng, caffeine, Ginkgo biloba, guarana, vitamins |
|Hansen's Slimdownc ||0 ||0 ||Pyruvate, carnitine, chromium, vitamins |
|Jones Whoop Ass Energyb ||107 ||27 ||Caffeine, royal jelly, guarana, taurine, inositol, vitamins |
|Mad River Energy Hammerb ||110 ||27 ||Guarana, ginseng, bee pollen |
|Nexcitea ||100 ||21 ||Guarana, damiana, Schizandrae, mate, ginseng, caffeine |
|Oxytime+ Sports Drinkh ||80 ||18 ||"Stabilized oxygen," carnitine, aloe vera, protein |
|Prozone Fat-Reducing Energy Drinkg ||184 ||19 ||Protein, medium-chain triglycerides, borage oil |
|Pripps Amino Energy Sports Drinki ||71 ||17 ||Protein, branched-chain amino acids, electrolytes |
|Pyru Forcef ||2 ||0.4 ||Caffeine, pyruvate, guarana, choline, chromium, inositol, carnitine, vitamin C |
|Red Bullb ||109 ||27 ||Taurine, caffeine, inositol, vitamins |
|Red Devil Energy Drinkb ||80 ||21 ||Caffeine, taurine, guarana, ginseng, Ginkgo biloba, vitamins |
|Sobe Adrenaline Rushb ||135 ||35 ||Caffeine, taurine, ribose, carnitine, inositol, ginseng, vitamins |
|Sobe Energyb ||113 ||30 ||Caffeine, guarana, arginine, L-cysteine, yohimbe, vitamin C |
|Sobe Powerb ||107 ||28 ||Caffeine, taurine, creatine, proline, vitamin C |
|Ultrafit Liquid Endurancee ||N.A. ||N.A. ||Glycerol, carnitine, chromium, vitamin B6 |
|VAAMj ||56 ||10 ||17 amino acids |
|Venom Energy Drinkb ||127 ||28 ||Caffeine, taurine, mate, bee pollen, guarana, ginseng, protein, vitamins |
|180 Energy Drinkb ||117 ||32 ||Guarana, vitamins |
Implications for Activity
The consumption of sports drinks and energy drinks has two different objectives for the athlete. A sports drink is designed to replace electrolytes lost during exercise and return the athlete's body to a normal state of hydration. Sports drinks are helpful to the athlete during and after exercise and do not produce adverse effects, even when consumed with medications. Energy drinks are designed by the manufacturer to provide an energy boost and not to replace lost electrolytes. The use of energy drinks can produce adverse effects in the athlete when they are mixed with other natural supplements or with prescription or OTC medications. Energy drinks can also produce a positive drug test if an athlete drinks significant amounts.
Some athletes and researchers have experimented with various styles of dietary supplementation based on the rationale that what and when you eat can provide an ergogenic effect. The most common dietary technique is carbohydrate loading, but other diets are circulated and published every few years.
Carbohydrate loading uses muscular stores of glycogen at the beginning and end of the physical activity. Advocates of this technique argue that consuming extra carbohydrate provides increased energy for the endurance athlete. This is the idea behind a pasta dinner the night before a marathon or triathlon. The athlete is putting extra carbohydrates into the body just before the endurance-based competition. The concept of a "depletion phase" (a near-maximal effort that depletes the muscles' glycogen stores about 3 to 4 days before actual competition) before the actual carbohydrate loading begins is now under close scrutiny by many researchers. In the early 1970s, when carbohydrate loading schemes were originally being published in the scientific literature, a depletion phase was said to be critical for the technique to be effective. After what was considered the complete depletion of muscle glycogen, the athlete would eat as many carbohydrates as possible with the idea that the "starving" muscle tissue would grasp and hold on to all the carbohydrates eaten. This, then, would provide more carbohydrate and muscle glycogen availability for the body to access during the competition. For competitions lasting over an hour, carbohydrate loading was viewed as the best technique to improve performance.
A major drawback to this tactic was the adverse effects associated with the nutritional imbalance created by complete depletion of carbohydrate stores. Athletes who strictly followed their high-intensity workouts without any carbohydrates in their diet complained of overwhelming fatigue, generalized irritability, and a reduction in overall performance during the training cycle leading up to the competition. Additionally, the athletes complained of not being able to find foods that they liked to eat, which were composed mainly of fats and proteins. In the 1980s further research indicated that this strict depletion period was not essential to carbohydrate loading, and some athletes then began eating some carbohydrates during the depletion phase. There are still athletes who believe that complete abstinence from carbohydrates is critical for the scheme to work properly.
Today most athletes claim that a closely followed carbohydrate loading scheme will improve their performance in an endurance competition by about 2 to 3 percent. Table 13–4 is an example outline of how an athlete could utilize carbohydrate loading before an important competition.
Table 13–4Carbohydrate Loading Scheme ||Download (.pdf) Table 13–4 Carbohydrate Loading Scheme
|Breakfast ||3 cups low fiber cereal with 1½ cups low-fat milk |
|1 banana |
|1 glass orange juice |
|Midmorning Snack ||Muffin (with honey or jam) |
|18 oz. sports drink |
|Lunch ||2 sandwiches (4 slices bread; low-fat meat, e.g., turkey) |
|8 oz. yogurt |
|12-oz. drink of choice |
|Afternoon Snack ||Smoothie with low-fat milk (banana, etc.) |
|Cereal bar |
|Dinner ||2 cups cooked pasta with 1 cup sauce |
|3 slices bread (garlic, etc.) |
|Drink (18 oz. sports drink, etc.) |
|Night Snack ||Muffin (with honey or jam) |
|18 oz. sports drink |
Other dietary techniques are being promoted by various authors and researchers as ways to improve athletic performance. One of the diets with a vast following is the Zone Diet, which has been given credit for improving performance by a number of United States swimmers who won gold medals in the 1992 Barcelona Olympics and a variety of other athletes who won gold medals in the 1996 Atlanta The Zone Diet requires an athlete to have a fairly extensive understanding of nutrition and physiology. The idea behind this diet is to closely monitor nutritional intake and consume specific percentages of fats, proteins, and carbohydrates. The recommended percentages in the Zone Diet are 40 percent carbohydrate, 30 percent protein, and 30 percent fat. This diet requires a personalized program for each athlete that focuses on the total nutrients consumed. Once an athlete knows the exact amount of nutrients he or she consumes and can determine which group each food source fits into, he or she can consume the correct percentages. This diet requires a great deal of attention to what is being eaten each day. Improving athletic performance through the use of the Zone Diet has not been demonstrated through controlled research studies published in scientific journals.
Athletes are sometimes taught that adding vitamins, minerals, or amino acids to their diet can increase their athletic performance. In the United States, the general population and most athletes are getting enough vitamins and minerals in their daily diet. The exception may be the economically disadvantaged athlete. If an athlete is not getting a normal diet, as may be the case with a wrestler who must follow a calorie-restricted diet for many months, he or she might benefit from vitamin or mineral supplementation.
It is generally accepted that vitamin supplementation, specifically, vitamin E and C supplementation, has no effect on athletic performance or on postexercise recovery of tissues.11,49,53 However, there appears to be some potential long-term benefit in vitamin E supplementation for endurance athletes. Many endurance athletes use vitamin E as a prophylactic measure to reduce cholesterol buildup and as an antioxidant. A recent study has shown that an endurance athlete using vitamin E on a regular basis has a reduced potential for atherosclerosis and elevated cholesterol levels.53 It is suggested that this is a result of the vitamin combining with cholesterol and preventing it from depositing on blood vessel walls. This, in turn, reduces the likelihood of clogging and reduction in blood flow.
The use of zinc has also been suggested to be helpful to the athlete because of its role in cellular metabolism. However, the decrease of zinc in the body is difficult to determine.35 Therefore it is difficult to ascertain if zinc supplementation is beneficial. If an athlete is experiencing a significant loss of body weight, anorexia, fatigue, and decreased endurance capabilities, he or she may be experiencing reduced zinc levels. The way to obtain zinc through the normal diet is by eating proteins, especially absorbable animal fats, along with other known sources of dietary protein.
In an athlete's diet, the consumption of amino acids is important for many reasons. Maybe the most important is for the rebuilding of tissues that have been damaged as a result of activity. Resistance training is especially hard on the muscle tissues, and amino acids are required for rebuilding. Most athletes in America consume a well-rounded diet, which provides the necessary proteins for athletes to repair and rebuild exercise-related muscle damage. The need of the body to rebuild damaged tissue fluctuates according to the type and exercise level of the athlete. Athletes engaged in resistance training on a daily basis contend that amino acid supplementation is critical for the rebuilding of damaged muscle tissue. The human body does maintain a small store of amino acids that are considered free and available to the system.34
The marketing of amino acids to the athlete generally follows one of two different methods. First, supplement makers market amino acid supplementation to athletes as necessary to rebuild muscle tissue from training and participation. Second, they claim that the use of amino acids will enhance athletic performance by sparing carbohydrates or by providing an extra energy source for the muscles. Neither of these claims has been demonstrated in well-conducted scientific studies. Studies published in scientific journals report that there is no ergogenic effect from an increased intake of supplemental amino acids.55
As an example of how amino acids are marketed, one Website (www.xsportsnutrition.com) sells various types of amino acids. The consumer is encouraged to pick one or more based on their desired outcome. The primary claim is that amino acids will improve muscle-building potential and promote faster recovery and improved performance from training. One particular type of amino acid product is said to contain three essential branch chain amino acids. The recommended dosage is 2 to 4 tablets on an empty stomach 3 times a day before meals. The cost is $34.99 for 160 tablets, and a 6 week minimum is said to be needed before results are seen.
Some companies market a specific type of amino acid, glucosamine, which is alleged to restore or replace articular cartilage. These companies suggest that their products will have a healing effect as the glucosamine combines with the available cartilage fibers and restores damaged cartilage. This is a controversial area, and a significant amount of scientific inquiry is currently being made into this theory. To date, there is no definitive evidence of the long-term effect of amino acids as an articular cartilage repair mechanism. There is sufficient evidence to establish that amino acids, specifically glucosamine sulfate, will not repair damage done to articular cartilage from athletic injuries.25
Athletes need to realize that amino acids are water soluble. The body does not store vast quantities of amino acids, and any excess is excreted via the urine. The body takes and uses the amount of amino acids it requires from the regular diet or via supplementation and wash out whatever is unused.
Another type of amino acid currently being marketed is whey, the protein derived from milk. It is sold as a powder to be mixed with either water or skim milk. Whey contains less fat than regular milk (some products actually contain no fat) and the lactose can also be removed, so whey can be used by individuals with lactose intolerance. Whey proteins are considered to have a higher percentage of branch chain amino acids, which accelerate muscle protein replacement. These proteins are considered to have an increased bioavailability and solubility, making them more effective than other amino acids. Whey is marketed as a product that will increase insulin secretion and enhance the anabolic effects of insulin. The marketers claim that enhanced insulin production will result in an increase in protein synthesis. This resultant increase in protein synthesis will increase the repair of damaged muscle and even increase the size and overall capability of the muscle.
Whey is sold as a powder and comes in different flavors and container sizes. One manufacturer sells a 2-pound container for $59.99. This manufacturer recommends that users mix 2 scoops in 4 ounces of water or skim milk and use the product 2 to 3 times a day. Again, the manufacturer suggests that the product must be used for a minimum of 6 weeks before the consumer will see any changes.
Some prescription drugs, meant for use in legitimate medical conditions, are being used by elite athletes to gain an advantage. One of these prescription drugs is erythropoietin alpha (EPO), a blood product that sends a signal to the body to produce more red blood cells (RBCs). RBCs deliver oxygen to the muscles, organs, and tissues of the body. The more oxygen one can get to a muscle, the longer the muscle can function and the longer one can endure muscle contraction after muscle contraction. In an endurance activity such as a marathon, the muscles continually contract for hours at a time. The ability to deliver more oxygen to the muscles in this situation is a definite advantage for the athlete. Therefore, some athletes inject EPO as part of their overall preparation as they are readying for competition. They believe that their training will be enhanced by the extra oxygen available to the muscles and their competitive effort will increase.
Originally, EPO was extracted from the pituitary gland of a cadaver and was expensive and difficult to obtain. It is now synthesized in the laboratory and can be prescribed by a physician, so it is much less expensive and easy to obtain. Typically, EPO is prescribed for chemotherapy patients to increase their energy level and their ability to perform the activities of daily living while they are going through treatment.
Endurance athletes such as marathon runners, swimmers, and long-distance bicycle riders have discovered the advantages of having more red blood cells to transport oxygen. Yearly reports from the Tour de France and other bicycle races suggest that riders are using EPO to enhance their performance. The use of EPO is not easily detected by random drug testing, and the governing bodies of many different endurance-type sports are looking for laboratories that are able to perform tests to detect the use of EPO in athletes.
Theoretically, proof exists that EPO provides a mechanism to enhance athletic endurance. However, athletes should be warned not to attempt to supplement with EPO on their own or to use it on the advice of a fellow athlete. Too much EPO can cause the body to produce excessive amounts of red blood cells. This will require excessive work by the cardiac muscle and may lead to heart failure.
What to Tell the Athlete
When athletes are determined to use some type of substance to improve their performance, it is often difficult to help them understand the adverse effects that can result. Here are some tips for the athletic trainer when educating the athlete about these drugs:
Supplements containing ephedra are easily purchased "online" but can be dangerous to one's general health.
Athletes with certain types of cardiac irregularities who use ephedra can experience severe side effects and possibly death.
Supplements that claim to produce extra energy may contain high levels of caffeine.
The athletic trainer can safely encourage the liberal consumption of sports drinks to maintain hydration and electrolyte balance.
Encourage the athlete to use water-soluble vitamins, minerals, and amino acids if he or she is determined to use supplements.
The athlete should be discouraged from purchasing stimulants and supplements, especially via the Internet.
Before EPO was discovered, endurance bicycle riders were using a technique they called "blood doping" to improve their performance. The riders were taking blood from themselves 1 to 2 months before a competition, taking the RBCs out of the plasma, and then having them reinfused just before the race. Unfortunately, there was a great deal of experimentation with this method, and numerous bike racers died by reinfusing too many RBCs. This thickened the blood and made the heart overwork, resulting in heart failure and death. Blood doping is no longer a common practice among endurance athletes because EPO is now available.
Scenario from the Field
A 20-year-old female soccer player presented to the athletic trainer at her university with the following signs and symptoms. She had experienced bouts of syncope, her skin was pale, and she was experiencing an increase in blood pressure and some tachycardia. Her vital signs were fluctuating and she did not seem stable. She reported that she had been taking an OTC "thermogenic" or diet tablet to lose weight. She was in the athletic training facility at the university when she reported this. The athletic trainer quickly phoned the team physician and learned that he was on his way to campus for a scheduled clinic visit. The athletic training staff decided to wait a few minutes and monitor the athlete until the team physician arrived. When the physician arrived a few minutes later, the athlete was started on IV fluids. She did not respond as well as the physician expected, so she was transported to the local hospital. On arrival at the hospital, the athlete began to respond to the IV fluids and make a slow recovery.
Later it was documented that the athlete was taking an OTC supplement that contained ma huang, caffeine, willow bark, ginger, and some other ingredients. She reported that she was taking twice the amount recommended on the container. It was also determined, after the fact, that she had consumed only a bagel and a couple of diet soft drinks that day.
Athletes should be warned that doubling the dosage of any medication is not wise and that a lack of food intake, combined with exercise and overzealous supplement use, may lead to death. (Example courtesy of A Winterstein, PhD, ATC.)
Class Discussion Topics
Many athletes try to think of ways to increase their performance without having to work harder. What are some of the pros and cons of the use of the supplements discussed in this chapter?
An athlete is using herbal supplements, and the team physician prescribes a medication for the athlete, who does not think to tell the physician that she is taking an herbal supplement. As the athletic trainer, should you tell the physician if you know what type of herbal supplement she is taking?
Are sports drinks more effective than water in rehydrating the athlete during practice? After practice or a game?
A natural substance is not intended to improve performance, as is the intent of an ergogenic substance.
The DHSEA law delineated that food supplements marketed in the United States cannot claim to alter a disease process.
Supplement manufacturers can legally claim that their products will improve athletic performance.
Manufacturers marketing supplements do everything they can to make their product enticing for athletes.
When talking about nutritional supplements, the terms "natural" and "safe" are not the same.
There are a number of factors that affect the purity of a supplement.
Sports drink and energy drinks are different in their contents.
A successful carbohydrate-loading scheme requires a great deal of preplanning by the athlete.
Amino acids have a significant role in rebuilding damaged tissues but are not a major contributor to the overall general muscle-building process in a mature athlete.
EPO has been demonstrated to improve an athlete's performance if used correctly.