Athletes everywhere share a few common goals--to become faster, stronger and, most importantly, better at their sport. Basic nutrition is certainly a foundation in terms of keeping the body in good health, but competitors of all levels are looking for more than just basic shape--they want advantage. Reaching higher performance and ability levels of any active sport requires intense and consistent motivation, steadfast dedication and cultivated skills. However, sports supplements can provide some advantage or edge to many aspects of athletics.
According to Nutrition Business Journal (NBJ) data, the sports nutrition market totaled about $4.7 billion in revenues in 1999, with sports supplements alone selling $1.42 million.
The juggernaut of the sports supplement market is protein. Most commonly found in powder form, protein accounted for $500 million or 35 percent of total sports nutrition sales in 1999 (NBJ). Whey protein still reigns king with men, as the testosterone-heavy gender are hesitant to dabble with phytoestrogens in soy that could affect testosterone levels. Still, soy protein offers a competitive amino acid profile and, unlike whey, delivers many other potential health benefits, such as lowering cholesterol and decreasing risk of cancer.
Weight loss aids are also among the most popular sports supplements, demonstrating just how many "athletes" feel the need to slim down to an ideal figure. Thermogenic aids, specifically, accounted for $300 million or a little more than 20 percent of the total sports supplement market (NBJ). These products often contain ingredients such as caffeine, various forms of chromium and ephedra, which has been subjected to much scrutiny in recent years. Ephedra is a herbal, central nervous system stimulant that is revered by many weight loss hopefuls for its ability to depress appetite. Caffeine has similar actions and is often paired with ephedra, much to the chagrin of those concerned with safe supplement use.
Chromium is a bit more complicated. The mineral helps regulate the action of insulin, which is used to transport glucose, amino acids and fat to cells. Praised widely by many as a weight loss aid, it is also thought to increase lean muscle mass. As a transporter of amino acids, chromium may help build muscle protein leading to muscle mass. Despite its fans, chromium does not get endorsement from the American College of Sports Medicine (ACSM), which feels the research on chromium and muscle mass was not conducted correctly. The studies on chromium has produced mixed results, and the final word has not yet been spoken.
Other popular supplements for fat loss and lean muscle development include conjugated linoleic acid (CLA), caffeine, yohimbe and Citrus aurantium (bitter orange).
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Russian kayakers, bodybuilders, weightlifters and powerlifters given velvet antler experienced increased muscular and nerve strength. |
The last of the sports nutrition triad is creatine, which accounted for $230 million or 16 percent of the 1999 sports supplements market. Creatine is a protein found naturally in the body and is obtained from red meat. It is available in popular supplement form at higher concentrations than found in meat. The gist of creatine's action is in its revival of depleted adenosine triposphate (ATP), which is often dubbed the body's energy currency.
The remaining sports supplements combined for a total of about $120 million or 8 percent of the market but include a number of promising products that can help increase speed and strength, boost testosterone, burn fat and facilitate recovery from both depletion and injury.
Second Wind?
One of the toughest aspects of sport is having the energy to go the distance, complete the goal. Many supplements work at the cellular level to help sure up energy for immediate use and for the long haul.
Also popular for energy production is CoQ10, which is found in every cell in the body and aids in the delivery of oxygen throughout biologically active molecules. It supports ATP production in the mitochondria, an organelle that drives production of ATP.
Another substance active in the mitochondria and crucial to energy production is carnitine, which carries fat to mitochondria. Fat could not be turned into energy without carnitine. Furthermore, research has suggested that the level of carnitine in the body correlates directly to the level of energy. In a study published in Neuropsychobiology (1:16-23,1995), researchers found that when fatigue was at its highest, carnitine levels were low, and as carnitine levels rose, fatigue was less apparent. When 30 chronic fatigue syndrome patients were given 3 g of carnitine per day, symptoms decreased. Another study revealed that when athletes took supplemental carnitine, aerobic performance was enhanced (Intl J Sports Nut, 1992).
Pyruvate, the stable form of pyruvic acid, is another energy enhancing supplement naturally found in the body. Its chemical reactions promote mitochondrial action by stimulating cellular respiration, therefore increasing ATP production. It is also said to improve endurance in athletes by enhancing the process in which glucose is assimilated from the blood stream into the muscles, a process called "glucose extraction." This process draws the glucose from the blood into the cells, increasing energy production.
Other energy supplements that remain popular to sports nutrition consumers include Panax ginseng, NADH, bee pollen, flower pollen and B vitamins.
In sports, "survival of the fittest" is a common creed. So is "only the strongest survive." Clearly, by these notions, muscle rules. Body builders are among the sports nutrition industry's most loyal consumers, and the level of athletics played today demands participants in most sports to hit the weights regularly. With this in mind, nothing has drawn as much attention from the sports community and press as products taken to boost testosterone, the male hormone that can greatly affect muscle size.
Androstenedione is a precursor to testosterone. It is thought that androstenedione can increase muscle strength and size because of its close proximity to testosterone in the metabolic pathway. Although published and unpublished research has indicated that androstenedione increases testosterone levels by about 25 to 40 percent, there are no published studies to date that show that androstenedione increases muscle mass or strength in humans. A serious blow came when the June 2, 1999 issue of the Journal of the American Medical Association (JAMA) published the results of a study that showed that andro may not increase muscle size and strength and may also have adverse side effects.
As a result of andro's tarnished reputation in the media and its much debated status in the medical, scientific and sports communities, derivatives such as androstenediol and 19-nor-androstenedione have enjoyed more of the testosterone precursor spotlight.
Another pro-hormone, dehydroepiandrosterone (DHEA) is produced by the adrenal glands just before puberty, reaches peak levels in a person's mid 20s but diminish from 30 years of age until about 80. DHEA is converted in the body to androstenedione and then testosterone, but many experts contended that young men do not need DHEA supplementation because they naturally produce enough DHEA to maintain optimum testosterone levels.
Tribulus terrestris is often used in formulations with both androstenedione and DHEA for its believed ability to increase levels of luteinizing hormone (LH), a pituitary hormone that activates natural testosterone production. Also, it is thought that androstenedione can over time cause the body to shut down its own natural production of testosterone, which is the reason for including Tribulus terrestris in supplement formulations containing andro. By stimulating secretion of LH, Tribulus terrestris may counteract androstenedione's effect.
Aromatase inhibitors also are commonly featured in androstenedione formulas. Researchers have suggested that aromatase inhibitors block the pathway that turns androstenedione and testosterone into estrogen, which is the last thing an athlete looking for testosterone boost wants. A well-known aromatase inhibitor currently on the market is chrysin, or Flavone X, which inhibits cytochrome P-450 aromatase activity (which can cause an unwanted rise in estrogen concentrations).
There are numerous non-steroidal supplements that can increase testosterone levels. Velvet antler, which is harvested from elk and deer midway through its growing cycle, is rich in many nutrients including elevated levels of insulin growth factor (IGF-1), which can improve muscular development. Growth hormone levels decrease alongside decreasing IGF-1 levels as humans age, often leading to muscular atrophy. The animals are not killed during the procedure, and groups such as the New Zealand Game Industry Board set quality standards for harvesting.
Preliminary results of clinical trials conducted at the University of Alberta (UA) in Canada by sports medicine scientist Brian Fisher have shown that city police recruits and UA football players taking velvet antler had five or six times their normal blood testosterone levels.
Arkady Koltun, M.D., Ph.D., chairman of the Medical Committee for the Russian BodyBuilding Federation, found that Russian kayakers, bodybuilders, weightlifters and powerlifters given velvet antler experienced increased muscular and nerve strength. Plus, Russian scientist Korobkov reported that pantocrin and other nutrients found in velvet antler have helped accelerate natural restorative processes after intense workout.
Glutamine and HMB both work on maintaining muscle tissue and are two of the most promising nutrition ingredients, according to Lisa Dorfman, sports nutritionist and author of The Vegetarian Sports Nutrition Guide (John Wiley & Sons). "Glutamine provides a natural anabolic boost during resistance training," Dorfman said. Rehan Jalali, president of the Supplement Research Foundation, explained that glutamine can cause muscle fullness by promoting cell volumization, the drawing of water into the muscle cells. He noted that it also contributes to recovery by affecting the rate of protein turnover in muscles, boosting anti-inflammatory cell function and increasing muscle glycogen deposition.
ZMA™, a special combination of zinc, magnesium and vitamin B-6, has been found to impact athletic performance and testosterone levels. To enhance bioavailability, the zinc and magnesium are chelated. A study presented at the 46th annual meeting of the American College of Sports Medicine in 1999 found that nightly supplementation of ZMA™ increased total and free testosterone levels by more than 30 percent while also increased strength and power.
"ZMA is non-steroidal and won't cause undesirable side effects," stated Debasis Bagchi, director of research and development of InterHealth, which manufactures ZMA.
Zinc is a micro-mineral involved in the action of several hormones including insulin, growth hormone, testosterone and estrogen. Research has shown that exercising individuals are more prone to a zinc deficiency and, therefore, have a greater need for zinc supplementation. In a 1996 study, researchers found that healthy men experiencing moderate zinc deficiency who took 30 mg/daily of supplemental zinc doubled their testosterone levels in a 6-month time frame.
Magnesium is a macromineral involved in more than 300 enzymatic reactions including glycolysis, the krebs cycle, creatine phosphate formation, nucleic acid synthesis, amino acid activation, cardiac and smooth muscle contractability, cyclic AMP formation and protein synthesis (important for strength athletes).
Rounding out the ZMA™ formula is vitamin B-6 (also known as pyridoxine), which has some major affects on protein synthesis. The coenzyme form of this vitamin is associated with a vast number of enzymes, most of which are a part of amino acid metabolism. Vitamin B6 has also been shown to diminish the actions of certain catabolic steroids such as glucocorticoid hormones (cortisol).
Sports nutrition sells. It is one of the few segments of the dietary supplement industry that is experience positive growth. NBJ placed the entire sports nutrition market (including energy bars, pills and pre-mixed drinks) at a sales growth of 10 percent for 1999. Nutrition bars alone grew 28 percent in that year. The sports supplement market has hit the big leagues and could be a prosperous part of an health supplement retailer's business, especially in this year's softening market for vitamins, minerals and specialty supplements.
Teens and Supplement Use
Though it may seem that sports supplementation began with Mark McGwire, athletes have been using various supplements for many years to enhance performance, increase endurance and stave off injury. Some such supplements include creatine, ephedra, androstenedione (andro), dehydroepiandrosterone (DHEA), hydroxy methyl butyrate (HMB) and ribose. While many of the hormone supplements have been banned from professional and Olympic sports, and ephedra has become almost taboo, many collegiate and high school athletes are using supplements to build muscle mass and enhance performance, and the majority are not seeking professional advice in terms of which supplements to take.
A study published in the December issue of the Mayo Clinic Proceedings (75(12): 1257-63, 2000) reported that of 328 students surveyed, 27 athletes (26 male, one female) had used creatine. The majority of the creatine users reported getting information primarily from friends. Because teens do not generally seek professional advice, retailers can assist their education by providing research and literature explaining how supplements affect the body and what adverse effects are associated with them.
The Blue Cross and Blue Shield Association's Health Competition Foundation's Web site (www.healthycompetition.org) suggests that athletes abstain from using creatine because of anecdotal evidence that athletes have experienced cramping, diarrhea, nausea, dizziness, dehydration, incontinence, muscle strain, high blood pressure and abnormal liver and kidney function after using the supplement. However, creatine is still one of the more popular supplements among teenage athletes.
In research conducted in an NCAA Division I athletic program and published in the July issue of Clinical Journal of Sports Medicine (9(3): 167-9, 1999), all respondents who stated they had used (28 percent, or 208 athletes) or had heard of (68 percent, or 509 athletes) creatine said their major source of information was friends and teammates. One-third of the participants who reported using creatine said their first experience with the supplement was during high school.
"Normally, I see the young people dabbling in supplements probably around 14 or 15 when they first start getting into lifting and body building," said Jeanie Subach, M.A., R.D., and consulting dietitian for the Philadelphia Eagles football team and the Philadelphia 76ers basketball team. "The reason they start is because they're not seeing results based on what they're doing--because of improper training or unrealistic expectations--and they're trying to get the 'magic bullet,' a quick result. But all athletes need to start with good nutrition."
According to most experts, a "magic bullet" to enhanced athletic performance and a sculpted body does not exist, but a good beginning is in nutrition; however, this fact does not stop teenagers from taking supplements to improve athletic performance on the playing field. "Basically sports drinks, energy bars, creatine and protein powders" are the popular supplements among teenagers, said Nancy Clark, M.S., R.D., author of Nancy Clark's Sports Nutrition Guide Book, 2nd Edition, and director of nutrition services at Boston-based Sports Medicine Associates. Even so, Clark helps her clients focus on nutrition rather than supplementation. "It's important to look at what their goals are, and then to look at how they can reach their goals through nutrition," she said. "If they exhaust the nutrition possibilities, certainly there can be conversations about other options."
Teenagers are looking into supplementation on their own and taking most of their advice from friends. According to an article published in the June 2001 issue of Consumer Reports, "Sports Supplement Dangers," teenagers are, in essence, experimenting on themselves by taking "untested" supplements such as andro and ephedra, which the magazine cited as being the most dangerous supplements in the realm of sports nutrition. "Well, first of all, teens shouldn't be taking any of the hormone supplements," said Ed Burke, Ph.D., Director of Exercise Science Program at University of Colorado, Colorado Springs. "Any time you're talking DHEA or androstenedione or ephedra, those shouldn't be taken by anyone under the age of 21. And females, obviously, should be careful at any age with taking hormones." Consumer Reports supported its claims by citing a national 1999 Blue Cross and Blue Shield survey that reported six percent of 15- to 16-year-olds and eight percent of 17- and 18-year-olds surveyed (the majority of whom are male) had taken sports supplements.
Dr. J.D. Metzl published an article in Curr Opin Pediatr (11(4): 292-6, 1999) suggesting that young athletes were looking for ways to "win at all costs," including using nutritional supplements to improve performance and prevent injury. Metzl stated that physicians should regard nutritional supplements with "extreme trepidation in the pediatric and adolescent health communities" owing to the lack of research and long-term studies. "I don't think people under 18 should be taking supplements because no long-term studies have been done on this population," Subach said. "For younger athletes, the first thing they have to get down is their diet because any supplement they take is not going to give them a benefit if they're not eating properly."