In addition to glutamine, there has been interest in determining the role that other nutrients may have on immune function. From these studies, there appear to be several nutrients and or herbs that may help athletes maintain a healthier immune system during training. The first nutrient reported to enhance immune function is protein Studies indicate that immunosuppressed patients are often protein malnourished. Additionally, athletes who maintain a negative energy balance during training may also be susceptible to become protein malnourished. Protein supplementation in protein-malnourished patients has been shown to improve immune status Consequently, it is important that athletes eat enough quality protein in their diet to maintain a healthy immune system.

The second nutrient that may affect immune responses during training is vitamin C. Vitamin C is involved in the synthesis of epinephrine, iron absorption, and is an antioxidant. There is also evidence that vitamin C may enhance immune function. With regards to athletes, vitamin C supplementation (600 mg/day for 3 weeks) following an ultramarathon race was found to decrease the incidence of URTI by 33% following the event in comparison to athletes given a placebo These findings have led some to contend that athletes engaged in intensified periods of training should supplement their diet with vitamin C to help decrease the incidence of URTI.

More recently, zinc supplementation (25 to 100 mg/day) during the onset of symptoms of a cold or URTI has been reported to decrease the severity and length of the cold infection. Athletes have been reported to be commonly zinc deficient. Theoretically, zinc supplementation during intensified periods of training and or as athletes experience symptoms of a cold may help athletes stay healthier. To support this theory, one study reported that zinc supplementation (25 mg/day) during training minimized exercise-induced changes in immune function. However, more research is needed to test this hypothesis.

The last supplement that may be beneficial for athletes to enhance immune function is echinacea. Echinacea is a popular herb that has been reported to enhance the immune system in a similar manner as an antibiotic. Evidence suggests that echinacea can reduce the incidence, severity, and duration of colds and infections Theoretically, echinacea supplementation during periods of intensified training and/or as an athlete experiences symptoms of a URTI may help athletes stay healthy during training. However, although there is scientific support for use of echinacea, we are not aware of a study that has evaluated whether echinacea supplementation during training affects the incidence of URTI in athletes.

As a result of training, all of the various oxidative processes are elevated in both aerobic and anaerobic athletes. The magnitude of these elevations depends on the intensity and type of exercise in which one is engaged. Also, some authors have speculated that the oxidative muscle damage associated with exercise may lead to the termination of muscular effort. In light of this knowledge, researchers and lay people alike have speculated that antioxidant supplementation may level the playing field, reducing tissue damage and soreness, improving exercise performance, and even prolonging life span. But do we need nutritional supplements to protect us from oxidative damage Or can our bodies handle the stress naturally through homeostasis?

Regarding antioxidant homeostasis, most of the research done on endogenous antioxidant enzymes and their adaptation to exercise has been done using endurance protocols. From this research, aerobically trained individuals (including humans and rats) have elevated endogenous (produced within) antioxidant enzyme concentrations and/or activities compared with controls As the body adapts to the demands of an increased training load by increasing mitochondrial density, capillarization, stroke volume of the heart, etc., it also defends itself from the increasing amount of oxygen that is delivered and used by the muscle. Because mitochondrial density increases (there are more mitochondria per unit of muscle) in aerobically trained individuals and the antioxidant enzymes are located within the mitochondria, it only stands to reason that antioxidant activity would increase in endurance-trained individuals. Of course, the more mitochondria, the more potential for reactive oxygen species, so the question is whether the increased enzymes can deal with the increased free radicals.

In numerous studies, the activities of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) were increased in oxidative (type 1) skeletal muscle with endurance training. In addition, glutathione levels increase in response to training while oxidative damage is lessened when compared to untrained rats and humans. Although this suggests that trained individuals have a better protection from exercise-induced free radical damage than untrained, it cannot be assumed that the skeletal muscle of these individuals has enzyme levels that completely protect against free radical damage. Nor is it safe to assume that all athletes gain the same degree of antioxidant protection from training. Since enzymatic adaptations occur primarily in slow-twitch muscle fiber sand fast-twitch fibers do not, to a large extent, undergo such changes, athletes with a higher percentage of fast-twitch fibers like bodybuilders, sprinters, and power lifters may be more susceptible to free radical damage

The knowledge of training-induced endogenous antioxidant up regulation does, in fact, question the need for endogenous antioxidant supplementation. That is, why do athletes need an antioxidant boost when the body naturally adapts to exercise by improving its defenses Although the antioxidant capacity of the body is increased with endurance training, it appears that even these increases are often not sufficient to neutralize the increase in free radicals generated from long-duration aerobic exercise. It is clear that, depending on the type of exercise, free radical formation may supercede the body’s ability to protect itself, even in training-adapted individuals. In this case, it would be appropriate to increase the ingestion of exogenous antioxidants.

That said, the next relevant question would address whether the ingestion of foods that are high in bioavailable antioxidants would be sufficient to provide for the additional needs of specific populations or whether further antioxidant intake would be necessary. Since intense exercise training leads to the depletion of tissue and plasma concentrations of antioxidants such as coenzyme Q10 or ubiquinone, vitamin C, and vitamin E, this reduction may lead to a decreased antioxidant defense. This depletion is evident even in those athletes consuming a “nutritious, well-balanced, and mixed diet.” Hence, dietary intake may not provide sufficient amounts of antioxidants to athletes. By increasing tissue and plasma concentrations via antioxidant supplementation, athletes can assist endogenous antioxidant capacity and complement dietary intake to reduce the damage that results from strenuous training. Granted, antioxidants and nutrients seem to be better absorbed and seem to confer greater benefit when consumed as part of whole foods, but when whole food intake is insufficient, additional supplementation is the next best thing.

Of course thousands of people supplement vitamin C for its antioxidant properties. In fact, many consume several grams per day in an effort to reduce the damage that free radical compounds can cause. But is consuming such high doses beneficial In addition to the inefficiency of absorption as the vitamin C dose is increased, evidence also exists that large acute doses can result in opposing effects to what is intended. How can this be Because of the nature of redox reactions, a substance such as vitamin C could reduce certain cellular components (an antioxidant effect) while oxidizing others. The ability of vitamin C to do this has been reported repeatedly and may be related to dose. Podmore and colleagues (1998) showed that administration of 500 mg/ day to healthy humans for 6 weeks induced pro­oxidant effects on particular segments of nuclear material in lymphocytes. This suggests that higher doses actually act in a manner that is opposite to their intend­ed purpose for many people. And in an effort to elucidate a mechanism for vitamin C’s pro-oxidant effects, Paolini et al. examined very high dose supplementation (250 and 500 mg/kg for 4 days) in rats. The researchers showed a dose-response effect on superoxide anion production and an increase in microsomal oxidative enzymes, with the 500 mg/kg dose being substantially worse.

As shown in the new RDA for vitamin C was set by the Institute of Medicine’s Food and Nutrition Board to reflect tissue saturation. This 75-90 mg/ day recommendation may be exceeded with relative safety up to 2500 mg/day (the “Upper Limit”) but this does not ensure a total lack of pro-oxidant effects. To prevent selective oxidation of circulating blood components, it may be prudent to limit the daily dose of vitamin C to below 500 mg/day.

Charlatans thrive in the field of nutrition perhaps more so than in any other area of medical science. A quick glance through the business pages of the phone book will likely reveal many nutritionists who claim to be qualified nutrition-related consultants. Some sports supplement consumers will undoubtedly wish to consult with a nutrition professional to individualize and optimize their supplement program. But to whom should one turn to for accurate, unbiased sports supplement advice?

A listing in the table does not imply endorsement for an included credential, as many questionable credentials have been included. Rather, the table features an array of possible sports supplement advisors, despite whether or not they are truly qualified.

In most instances, accreditation means that an educational institution’s course credits will transfer to another school. Accreditation does not guarantee scientific accuracy, but does demonstrate that the program is well organized. All respected educational institutions are accredited.

Some institutions grant degrees, such as BS, MS, and even PhD degrees, but are not accredited. And unfortunately, some dishonest individuals use titles that they have not earned.

Because certain titles are not legally defined in all states, the person bearing a given title mayor may not have obtained a degree through an accredited institution. For example, some states have reserved the title of nutritionist for practitioners who have completed an appropriate college degree, whereas in other states anyone can call himself or herself a nutritionist regardless of educational background. Fake degrees that have been accredited by phony accrediting agencies add to the confusion. A legitimate accreditation agency must be recognized by the US Department of Education. To find out if a degree is from a properly accredited institution, a person may refer to the Accredited Institutions of Post-secondary Education Programs Candidates, which is published by the American Council on Education. This directory is available at many libraries, and lists accredited institutions, professionally accredited programs, and candidates for accreditation.

Licensure refers to a particular state’s recognition of an individual’s competence. Competence is commonly determined by passing a state licensure examination. Licensing provides a way to ensure that practitioners have met minimal standards of education and experience. A revocation of licensure does not negate a person’s academic credentials. For example, an unlicensed medical doctor, although unable to practice medicine, can still use the designation of MD and, in some states, may still be able to provide services as a nutritionist. To find out if a nutrition practitioner is licensed in the state in which he or she practices, the consumer should contact that particular state’s health-licensing agency. A standard name for such an agency does not exist, so a consumer may have to search the state government pages of the phone book for the appropriate agency

Traditionally, the primary health professional who dispenses nutritional information is the registered dietitian (RD), which requires the completion of a bachelor’s or master’s degree approved by the American Dietetic Association (ADA). However, the distinction of RD alone may not be sufficient enough to prepare a dietitian to become familiar with all of the sports supplements because of its rapid progression. Therefore, an RD should ideally be a member of the Dietary Practice Group (DRG) for Sports, Cardiovascular, and Wellness Nutritionists (SCAN), a section of the ADA having over 5000 professionals devoted to the application of sports nutrition. Becoming a SCAN member requires nothing more of the RD (or other ADA member) than paying a fee, but it does ensure that the RD has access to the latest scientific information in the field.

Other scholastically qualified individuals who may be good resources for scientific information on ergogenic aids include exercise physiologists, pharmacists, nutrition researchers, and physicians. These degrees alone are insufficient if the individuals have not specialized in nutrition as it relates to sport or if they have not actively and intensively self-studied such information. For example, the most desirable MDs and DOs for sports supplement consultation are those who have completed residencies in bariatrics (obesity), sports medicine, and endocrinology, or who have specialized in clinical nutrition. The academic/research degrees of BS, BA, MS, MA, PhD, and EdD offer expertise in any number of fields, from history to psychology and so on. Therefore, qualified individuals who hold these degrees should have specific backgrounds in biochemistry, nutritional biochemistry, nutritional physiology, nutrition, nutrition science, muscle physiology, exercise physiology, exercise science, or sports pharmacology.

The most common credentials of nonrecognized nutritionists are attained through certification rather than formal education. The difficulty of becoming certified varies greatly among the certifying bodies, but most certification organizations are not as rigorous as those that offer programs for becoming licensed. In fact, many certification organizations are correspondence courses that allow open-book examinations, which are graded liberally. In the past, some certifying bodies charged a fee in exchange for a fancy certificate, which led to household pets becoming recognized certificate holders.

Fortunately for the consumer, the days of unreliable nutritional consultation are numbered. The ADA has been leading a successful movement to restrict or prohibit unlicensed individuals from disseminating nutritional information. Essentially, the ADA is making dispensing nutritional information by an unqualified person analogous to practicing medicine without a license.

To summarize, the consumer can check the qualifications of an individual providing sports supplement information by first looking for the credential or degree abbreviations listed after the person’s name. Next, the reputation of the degree-granting institution can be checked through directories of accredited institutions. The consumer can also contact the health-licensing agency of the state in which the consultant practices to find out if the consultant meets the state requirements to advise clients in nutrition. To find out if a person is qualified as an RD, the consumer may contact the ADA.

Aerobic athletes produce physical work relatively slowly over long periods of time through the hydrolysis of ATP The demand for the re-synthesis of ATP to continue muscular work during prolonged exercise is met by the oxidation of fuel (carbohydrates, fats, and some protein) in the mitochondria. Under normal resting conditions the electron transport chain (ETC) of the mitochondria uses oxygen to produce ATP and during aerobic exercise this process is greatly accelerated. In fact, during aerobic exercise, oxygen processing occurs at rates fold above resting levels This accelerated oxygen processing contributes to increased free radical formation at the cytochrome level of the electron transport chain, with a two- to threefold increase in free radical levels.

Although ETC enzymes have evolved to efficiently process oxygen during the generation of ATP, even with this enzymatic efficiency, an estimated 2-5% of total oxygen flux through the mitochondria can form superoxide radicals at rest. It is speculated that, during exercise, the increased flow of oxygen through the ETC can lead to a significant increase in superoxide radicals beyond resting levels, In addition, at rest, endogenous antioxidants located in the mitochondria can effectively remove superoxide radicals but again, during exercise, the increase in oxygen radicals may be more than the endogenous antioxidants can neutralize.