Performance Enhancing Substances in Endurance Events

1. Performance EnhancingSubstancesin Endurance Events Kevin deWeber, MD, FAAFP Director, Primary Care Sports Medicine Fellowship USUHS

2. Objectives • Discuss substances used to enhance performance in endurance events • Discuss any medical evidence of their safety and effectiveness

3. Performance Enhancing Modalities • Mechanical • Psychological • Physiologic • Nutritional • Pharmacologic

5. Stimulants

6. Stimulants • Caffeine • Amphetamines • Cocaine • Sympathomimetics • Ephedrine • Pseudoephedrine • Phenylephrine • Phenylpropanolamine (PPA) • Modafinil

7. Stimulants – proven effects • Increases Endurance • Increases use of free fatty acids and triglycerides • Spares muscle glycogen early in exercise • Decreased perceived exhaustion • Enhances Anaerobic Exercise • Decreases time to exhaustion • Decreases perception of exertion • Hypoanalgesic effect • Small amount of weight loss

8. Stimulant Use Prevalence • Ephedrine: • 3.5% in NCAA athletes • Clin J Sports Med 2001 • 12% of HS boys/26% of girls have tried • Med Sci Sports Exer 2002 • Caffeine • 33% of British club track/field athletes • 60% of British club cyclists • Chester N, Int J Sports Med 2008

9. Caffeine’s Proven Effects • Increased time to fatigue in prolonged, moderate intensity exercise • No effect on repeated sprints/heavy exercise

10. Caffeine in Endurance Running • 4.2-sec faster 1.5-km • 1-3% faster 5-km • 24-sec faster 8-km • 50-sec faster 10-km military pack march • No change in 21-km race • Improved treadmill time-to-exhaustion in marathoners

11. Caffeine in Other Sports • Rowing: 1-3% faster 2000m race • Swimming: 24-sec faster 1500m race • About 21 min • Cycling: 3.5% higher mean power in 40km race

12. Caffeine Dosing • Doses 2-9 mg/kg in studies • 2-5 mg/kg usually effective • 250-500 mg • Cola: 40 mg • Coffee: 100 mg • Tea: 20-100 mg • Red Bull: 115 mg • Vivarin: 200 mg

13. Caffeinated Sports Drinks • No proven performance benefit • 18-km run times • Pl vs carb drink vs carb+150mg caffeine • consumed 4x in race • Int J Sports Med 2005

14. Ephedrine • 78-sec faster 10-km run (with backpack & helmet) vs placebo • 30-sec faster than caffeine • -0.8 mg/kg • No benefit when added to caffeine

15. Modafinil • Cycling at 85% VO2max • 22% longer time to exhaustion vs Placebo • 18.3 min vs 15.6 • Central mechanism: decreased RPE • Dose 4 mg/kg • No side-efx seen

16. Stimulants - Side Effects • Anxiety* • Dysrhythmias* • Hypertension* • Hallucinations • Addiction • Death

17. Stimulant regulation • Most banned by USADA & NCAA • Ephedrine • PPA • Most ADHD meds • Some still allowed (cold meds) • Pseudephedrine • Phenylephrine • Caffeine • USADA: no longer monitored • NCAA < 15 mcg/ml • 1 cup coffee = 100mg = 1.5 mcg/ml in urine

18. Blood Doping • Increasing the number of red blood cells in the body to increase the oxygen carried to muscle • Administration of blood, red blood cells, or related blood products • Erythropoietin • Stimulates bone marrow to produce red blood cells

19. Blood Doping – proven effects • 7% increase in Hgb • 5% increase in VO2 max • 34% increase in time to exhaustion at 95% VO2 max • 44 second improvement in 5 mile treadmill run time (Williams and Branch summarized study findings)

20. Blood Doping - Side Effects • Transfusion reactions • Infections • Increased viscosity of blood • Stroke, MI, PE

21. Blood Doping - regulation • Erythropoietin only by prescription • Doping banned by USADA, NCAA • Blood tested for antigens • Ceiling on allowable Hct level at 50

22. Beta-2-Agonists • Physiology • Bronchodilation, increased ventilation • Examples: albuterol, terbutaline, salmeterol

23. Beta-2-Agonists – proven effects • Clear benefit in asthma and EIB • Increased ventilation • No increase in performance in NON-asthmatic athletes • Side effects: tremor, tachycardia • Regulation • USADA: prohibited • NCAA: inhalation permitted

24. Creatine • Replenishes ATP in anaerobic exercise • No federal assessment of quality, performance, or safety • Proven to increase lean body mass, strength

25. Creatine – disproven effects • Meta-analysis 2003: • No significant difference in field-based athletic performance (e.g. running, swimming) X X X X X X X X Branch JD. Int J Sports Nutr Exerc Metab June 2003

26. Creatine - Side Effects • Studies of 2-10 weeks: no side efx • Long term: • 40% non-responders

27. Anabolic Steroids • Analogs of testosterone • More than 100 types • Forms: • Oral • Injection • Topical (gels, creams) • Prevalence of use • 2001: 1% in US college athletes • 2006: 13% of German fitness center attendees had used in past

28. Anabolic Steroids – Proven Effects • Increase in fat-free mass • Increase in body weight • Increase in arm girth • Increase in leg girth • Increase in bench press and squat scores

29. Anabolic Steroids—Disproven Effects • No effect on endurance exercise • Males on treadmill • Eur J Appl Physiol 2006 • VO2max in rats • Med Sci Sports Exer 2004

30. Anabolic Steroids - Side Effects • Hepatocellular damage • Cardiovascular disease • Psychological disturbance Effects can sometimes be permanent!

31. More side effects… • Men • Acne • Premature baldness • Prostatic hypertrophy • Female masculinization • Injection complications* • Testicular atrophy • Impotence* • Gynecomastia* (some may be permanent)

32. Nitric Oxide-releasing agents • Physiology • Arginine is a precursor of NO • NO regulates BP and blood flow to organs • Most supplements: Arginine α-ketoglutarate • Claims • Improves “pump” and blood flow to muscles • Increases strength and size • Speeds recovery

33. Nitric Oxide-releasing agents • Endurance exercise studies • No benefit in endurance athletes • Limited evidence of benefit in debilitated pts • Strength exercise: mixed results, no proven benefit • More studies needed

34. Sodium Bicarbonate • Mechanism: buffers metabolic acidosis after strenuous exercise • Proven ergogenic efx in high-intensity exercise • 100m & 200m swim • Repeated sprints • Repeated judo throws

35. Bicarbonate • Limited & conflicting evidence of benefit in aerobic exercise • High-intensity running: 17% better time-to-exhaustion (30 vs 26 min) • 60-min max-effort cycle ergometry: 14% higher power vs Placebo • 60-min high-intensity cycling: no difference vs Placebo

36. Bicarbonate • Dose: 0.2 - 0.3 mg/kg • GI side effects common

37. Carbs • Sports drink consumption • Carbohydrate loading

38. Sports Drink Consumption • Evidence supports enhanced endurance performance vs water in events >60 min • No benefit from added protein

39. Carbohydrate Loading • Known to increase muscle glycogen levels 13% - 100% • Prolongs time to exhaustion 2-3% in endurance events >90 minutes • Higher effect in Untrained persons • 25-km treadmill

40. Methods of Carbo Loading • Classic 6-day regimen • 3 days intense glycogen-depleting exercise • 3 days high-CH diet, no exercise • Modified 6-day regimen • 3-day exercise taper, normal diet • High-CH (70%) & light exercise 3d prior • Single-day regimen • 10 gm/kg/day CH 1-day prior • Normal exercise regimen

41. Carbohydrate Loading ‘s • Little standardization of methods • Athletes need to try methods prior to competition to see what works • Exact roles of glycogen-depleting exercise, type of CH, and timing are unclear

42. Miscellaneous Losersin endurance exercise performance • Vitamin E and other vitamins • Minerals: Cr, Mg, Zn, Se • L-Carnitine • Antioxidants • Pyruvate • Arginine • Hydroxy-methyl-butyrate (HMB)

43. Anti Doping in Elite Athletic Competition • Permitted/Prohibited? http://www.usantidoping.org.dro 1-800-233-0393

44. Therapeutic Use Exemptions- “TUE” • Abbreviated TUE • Doc fills out; athlete faxes to USADA • Effective immediately, up to 1 year • IM/IJ/inhaled corticosteroids • Inhaled beta-agonists • Regular TUE • All other substances • Doc fills out, send to USADA, along with supporting documents • Process takes 1-2 months to approve • Variable duration

45. No substitute for hard work… Questions?

46. Thank You!