External and internal motives to enhance performance often encourage athletes to consider the enticing marketing and testimonials surrounding supplements and sports foods. Sports supplements represent an ever growing industry, but a lack of regulation of manufacture and marketing means that athletes can fall victim to false advertising and unsubstantiated
claims.137 The prevalence of supplementation among athletes has been estimated internationally at 37%–89%, with greater frequencies being reported among elite and older athletes. Motivations for use include enhancement of performance or recovery, improvement or maintenance of health, an increase in energy, compensation for poor nutrition, immune support, and manipulation of body composition, yet few athletes
undertake professional assessment of their baseline nutritional habits. Furthermore, athletes_ supplementation practices are often guided by family, friends, teammates, coaches, the internet, and retailers, rather than sports dietitians and other sport science professionals. Considerations regarding the use of sports foods and supplements include an assessment of efficacy and potency. In addition, there are safety concerns due to the presence of
overt and hidden ingredients that are toxic and the poor practices of athletes in consuming inappropriately large doses or problematic combinations of products. The issue of compliance to anti-doping codes remains a concern with potential contamination with banned or non-permissible substances. This carries significant implications for athletes
who compete under anti-doping codes (eg, National Collegiate Athletic Association, World Anti-Doping Agency). A supplement manufacturer_s claim of ‘‘100% pure,’’ ‘‘pharmaceutical grade,’’ ‘‘free of banned substances,’’ ‘‘Natural Health Product – NHPN/NPN’’ (in Canada) or possessing a drug identification number are not reliable indications that guarantee a supplement is free of banned substances. However, commercial, third-party auditing programs can independently screen dietary supplements for banned and restricted substances in testing facilities (ISO 17025 accreditation standard)140 thereby providing a greater assurance of supplement purity for athletes concerned about avoiding doping violations and eligibility.
The ethical use of sports supplements is a personal choice and remains controversial. It is the role of qualified health professionals, such as a sports dietitian, to build rapport with athletes and provide credible, evidence-based information regarding the appropriateness, efficacy and dosage for the use of sports foods and supplements. After completing a
thorough assessment of an athlete_s nutritional practices and dietary intake, sports dietitians should assist the athlete to determine a cost to benefit analysis of their use of a product, noting that the athlete is responsible for products ingested and any subsequent consequences (ie, legal, health, safety issues). The benefits of the use of supplements and sports foods include practical assistance to meet sports nutritional goals,
prevention or treatment of nutrient deficiencies, a placebo effect, and in some cases, a direct ergogenic effect. However, this must be carefully balanced against risks, and the expense and potential for ergolytic effects. Factors to consider in the analysis include a theoretical analysis of the
nutritional goal or performance benefit that the product is to address within the athlete_s specific training or competition program, the quality of the evidence that the product can address these goals, previous experience regarding individual responsiveness, and the health and legal consequences.
Relatively few supplements that claim ergogenic benefits are supported by sound evidence.139,141 Research methodologies on the efficacy of sports supplements are often limited by small sample sizes, enrollment of untrained subjects, poor representation of athlete sub-populations (females,
older athletes, athletes with disabilities, etc.), performance tests that are unreliable or irrelevant, poor control of confounding variables, and failure to include recommended sports nutrition practices or the interaction with other supplements.139,141 Even when there is a robust literature on a
sports supplement, it may not cover all applications that are specific to an event, environment, or individual athlete. Supplement use is best undertaken as an adjunct to a wellchosen nutrition plan. It is rarely effective outside these conditions and not justified in the case of young athletes who can make significant performance gains via maturation in age, sports experience, and the development of a sports nutrition plan.