Performance-Enhancing Substances Jay R. Hoffman, PhD; CSCS,*D; FACSM; FNSCA Jeffrey R. Stout, PhD, CSCS, FACSM, FISSN, FNSCA chapter 9 Performance- Enhancing Substances

Chapter Objectives Provide reliable information to athletes on the risks and benefits of performance- enhancing substances. Evaluate advertising claims for over-the- counter supplements marketed for performance benefits. Describe the current status of research on performance-enhancing supplements.

Key Term ergogenic aid: Any substance, mechanical aid, or training method that improves sport performance; for the purposes of this chapter, the term refers specifically to pharmacological aids.

Section Outline Types of Performance-Enhancing Substances

Key Point The distinction between a drug and a dietary supplement is linked to FDA approval for safety and effectiveness.

Types of Performance- Enhancing Substances Definition of Products That Can Be Sold as Dietary Supplements –A product (other than tobacco) intended to supplement the diet that contains one or more of the following dietary ingredients: A vitamin A mineral An herb or other botanical An amino acid (continued)

Types of Performance- Enhancing Substances Definition of Products That Can Be Sold as Dietary Supplements (continued) –A product (other than tobacco) intended to supplement the diet that contains one or more of the following dietary ingredients: A dietary substance for use by humans to supplement the diet by increasing the total dietary intake A concentrate, metabolite, constituent, or extract (or combination of any ingredient identified above) (continued)

Types of Performance- Enhancing Substances Definition of Products That Can Be Sold as Dietary Supplements (continued) –The product must also be intended for ingestion and cannot be advertised for use as a conventional food or as the sole item within a meal or diet.

Section Outline Hormones –Anabolic Steroids Dosing Who Uses Anabolic Steroids? Ergogenic Benefits –Muscle Mass and Strength –Athletic Performance Psychological Effects Adverse Effects (continued)

Section Outline (continued) Hormones –Testosterone Precursors (Prohormones) –Human Chorionic Gonadotropin –Insulin –Human Growth Hormone Efficacy Adverse Effects –Erythropoietin –β-Adrenergic Agonists –β-Blockers

Hormones Anabolic Steroids –The synthetic (man-made) derivatives of the male sex hormone, testosterone

Table 9.1

Hormones Anabolic Steroids –Dosing Athletes typically use anabolic steroids in a “stacking” regimen, in which they administer several different drugs simultaneously. The potency of one anabolic agent may be enhanced when it is consumed simultaneously with another anabolic agent. (continued)

Hormones Anabolic Steroids –Dosing (continued) Most users take anabolic steroids in a cyclic pattern, meaning that they use the drugs for several weeks or months and alternate these cycles with periods of discontinued use. Often athletes administer the drugs in a pyramid (step-up) pattern in which dosages are steadily increased over several weeks. Toward the end of the cycle, the athlete “steps down” to reduce the likelihood of negative side effects.

Dose-Response Curve Figure 9.2 (next slide) –Dose–response curve of anabolic steroids and changes in lean body mass

Figure 9.2 Reprinted, by permission, from Hoffman, 2002.

Hormones Anabolic Steroids –Who Uses Anabolic Steroids? Olympic athletes, professional athletes, collegiate athletes, and high school athletes have been reported to use steroids. Many users are not involved in sports; they use steroids to improve appearance. –Ergogenic Benefits Muscle Mass and Strength –Increases in muscle protein synthesis with steroid use are likely responsible for increases in lean body mass. –Changes occur in both recreationally trained and competitive athletes.

Fat-Free Mass Figure 9.3 (next slide) –Changes in fat-free mass with anabolic steroid administration (200 mg/week nandrolone decanoate for eight weeks) and following drug cessation –*p <.05

Figure 9.3 Adapted, by permission, from Van Marken Lichtenbelt et al., 2004.

Hormones Anabolic Steroids –Ergogenic Benefits Athletic Performance –The purported ergogenic benefits commonly attributed to anabolic steroid use are increased muscle mass, strength, and athletic performance, but these changes depend on the training status of the individual.

Hormones Anabolic Steroids –Psychological Effects Anabolic steroid use is associated with changes in aggression, arousal, and irritability. –Adverse Effects The medical problems related to anabolic steroids may be somewhat overstated. Many of the side effects linked to abuse are reversible upon cessation. Side effects differ between anabolic steroid use under medical supervision and consuming many drugs at high doses.

Table 9.2

Hormones Testosterone Precursors (Prohormones) –Although performance changes may not occur with prohormone use, athletes may be at higher risk for experiencing adverse side effects similar to those associated with anabolic steroid use.

Hormones Human Chorionic Gonadotropin –When injected into men, HCG can increase testicular testosterone production. Insulin –Insulin increases protein synthesis, but the side effect of hypoglycemia can be fatal.

Hormones Human Growth Hormone –Efficacy There are no studies on the efficacy of HGH in athletic populations. Anecdotal reports suggest impressive musculoskeletal performance changes in athletes using HGH.

Key Point The anabolic potential of human growth hormone (HGH) and its ability to reduce body fat have contributed to the rise in HGH use among athletes.

Hormones Human Growth Hormone –Adverse Effects Although growth hormone used as replacement therapy for people with growth hormone or IGF-I deficiency can be effective and can have minimal adverse consequences, the dosages that are likely used by athletes may pose a significant risk for acromegaly.

Hormones Erythropoietin –Injections of EPO are associated with elevations in both hematocrit and hemoglobin. –Health risks include increased risk of blood clotting, elevations in systolic blood pressure, a compromised thermoregulatory system, and dehydration during aerobic endurance events. β-Adrenergic Agonists –β-adrenergic agonists can increase lean mass and decrease stored fat. β-Blockers –β-blockers reduce anxiety and tremors during performance.

Key Point More research is needed to examine the effect of many ergogenic aids in athletic populations. Athletes should not miscon- strue a lack of scientific information as an indication of safety.

Section Outline Dietary Supplements –Essential Amino Acids –β-Hydroxy-β-Methylbutyrate –Nutritional Muscle Buffers β-Alanine Sodium Bicarbonate Sodium Citrate –L-Carnitine –Creatine Importance of Creatine to Exercise Creatine Supplementation (continued)

Section Outline (continued) Dietary Supplements –Creatine (continued) Ergogenic Benefits Body Mass Changes Adverse Effects –Stimulants Caffeine –Efficacy –Adverse Effects Ephedrine –Efficacy –Adverse Effects Citrus Aurantium

Dietary Supplements The sport supplement industry throughout the world has exploded, with more than 600 sport nutrition companies marketing over 4,000 products that produce annual sales of more than $4 billion in the United States alone.

Dietary Supplements Essential Amino Acids –EAA can augment muscle protein synthesis in healthy human subjects. β-Hydroxy-β-Methylbutyrate (HMB) –It is believed that HMB has both anabolic and lipolytic effects, but research is limited. Recent studies do not support HMB supplementation in resistance-trained athletes.

Dietary Supplements Nutritional Muscle Buffers –β-Alanine –Sodium Bicarbonate –Sodium Citrate L-Carnitine –Studies examining L-carnitine’s role as an ergogenic aid for increasing lipid oxidation have not shown clear efficacy. –L-carnitine may enhance recovery from exercise.

Dietary Supplements Creatine –Importance of Creatine to Exercise The ability to rapidly rephosphorylate ADP is dependent upon the enzyme creatine kinase and the availability of creatine phosphate (CP) within the muscle. –Creatine Supplementation Creatine supplementation increases the creatine content of muscles by approximately 20%, but there is a saturation limit. –Ergogenic Benefits Studies consistently show significant ergogenic benefits.

Key Point Creatine, in the form of creatine phosphate (CP; also called phosphocreatine [PCr]), has an essential role in energy metabolism as a substrate for the formation of adenosine triphosphate by rephosphorylating adeno- sine diphosphate (ADP), especially during short-duration, high-intensity exercise.

1RM Squat Strength Figure 9.4 (next slide) –Changes in 1RM squat strength in experienced collegiate American football players ingesting creatine, creatine plus β-alanine, or a placebo –* = significantly different (p <.05) compared to placebo

Figure 9.4 Adapted, by permission, from Hoffman et al., 2006.

Key Point Creatine supplementation has been shown to increase strength and improve training by reducing fatigue and enhancing postworkout recovery.

Dietary Supplements Creatine –Body Mass Changes Prolonged creatine supplementation has been generally associated with increases in body weight, especially increases in fat-free mass. –Adverse Effects Controlled studies have been unable to document any significant side effects from creatine supplementation. Concerns include gastrointestinal disturbances and strain on the kidneys.

Dietary Supplements Stimulants –Caffeine Efficacy –Increases time to exhaustion –Effects on sprint or power performance unclear Adverse Effects –Many adverse effects, including anxiety, gastrointestinal disturbances, restlessness, insomnia, tremors, heart arrhythmias, and increased risk for heat illness –Is physically addicting

Key Point A central nervous system stimulant, caffeine is an ergogenic aid that may enhance perfor- mance in aerobic and anaerobic athletes alike.

Dietary Supplements Stimulants –Ephedrine Efficacy –Effective only when it is taken in combination with caffeine –Improves aerobic endurance performance Adverse Effects –Many adverse effects, including death –Banned by most sport governing bodies, including the International Olympic Committee

Dietary Supplements Stimulants –Citrus Aurantium Is thought to contribute to appetite suppression, increased metabolic rate, and lipolysis When combined with caffeine and other herbal products, significant improvements in time to fatigue have been reported On NCAA list of banned performance-enhancing drugs