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Chapter 16

Chapter 16. Ergogenic Aids and Sport. Chapter 16 Overview. Researching ergogenic aids Pharmacological agents Hormonal agents Physiological agents Nutritional agents. Ergogenic Aids Introduction. Ergogenic (“work producing”) versus ergolytic (“work breaking”) substances Potential aids

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Chapter 16

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  1. Chapter 16 • Ergogenic Aids and Sport

  2. Chapter 16 Overview • Researching ergogenic aids • Pharmacological agents • Hormonal agents • Physiological agents • Nutritional agents

  3. Ergogenic Aids Introduction • Ergogenic (“work producing”) versus ergolytic (“work breaking”) substances • Potential aids • Pharmacological agents • Hormones • Physiological agents • Nutritional agents

  4. Table 16.1

  5. Table 16.1 (continued)

  6. Researching Ergogenic Aids • Must be proven to enhance performance • Claim alone insufficient • True ergogenic versus pseudoergogenic responses • Placebo effect • Placebo: inactive substance that looks like the real thing • Expectations affect physiological response • Double-blind experimental design

  7. Figure 16.1

  8. Researching Ergogenic Aids • Scientific results may not provide clear answers to ergogenic questions • May be able to prove ergogenic action • Results often equivocal • Factors that can limit research • Technique, equipment inaccuracy • Research methodology • Testing situations (lab vs. field)

  9. World Antidoping Code: Criteria for Prohibited Substance 1. Substance or practice has the potential to enhance sport performance 2. Substance or practice has the potential to harm the athlete 3. Substance or practice violates the spirit of sport

  10. Pharmacological Agents • Must know all drugs taken by the athlete • Therapeutic use exemption in advance for certain medical circumstances • Otherwise athletes may forfeit medals, prizes, awards • Check drugs versus banned substances list • Examples: sympathomimetic amines, b-blockers, caffeine, diuretics, recreationally used drugs

  11. Pharmacological Agents:Sympathomimetics • Sympathomimetic amines • Amphetamines (also ephedrine, pseudoephedrine) • Medical and ergogenic applications • Proposed benefits of amphetamines • Weight loss • Heighten concentration and focus • Make athletes more competitive, induce sense of being indestructible and euphoria • Enhance performance, delay fatigue

  12. Pharmacological Agents:Sympathomimetics • Proven effects of amphetamines –  State of arousal, energy, self-confidence –  Fatigue –  HR, blood pressure, blood flow, blood glucose, FFAs • Enhance performance by –  Weight loss • Improving reaction time, speed, and focus –  Strength, power –  Max HR, peak lactate

  13. Pharmacological Agents:Sympathomimetics • Risks of amphetamines, ephedrine • Death, toxicity • Heatstroke, cardiac stress • Addiction (psychological, physiological) • Masking of physiological danger signals • Ephedrine and pseudoephedrine lack benefits but still carry significant risks

  14. Pharmacological Agents:b-blockers • b-blockers reduce sympathetic effects • Used to treat cardiovascular disease • Also for migraines, anxiety, stage fright • Proposed benefits of b-blockers • Decrease performance anxiety • Enhance physical steadiness

  15. Pharmacological Agents:b-blockers • Proven effects of b-blockers –  Resting, submaximal, and maximal HR –  Hand stability • Risks of b-blockers • Bronchospasm in asthmatics • Cardiac failure, low blood pressure/dizziness • Hypoglycemia (type II diabetics) • Fatigue, impaired performance

  16. Pharmacological Agents:Caffeine • Caffeine • Central nervous system stimulant • Sympathomimetic effects (but weaker) • Proposed benefits of caffeine –  Mental alertness, feel more competitive • More energy, reduced or delayed fatigue • Enhanced mobilization of FFAs • Glycogen sparing

  17. Pharmacological Agents:Caffeine • Proven effects of caffeine –  Alertness, concentration, and mood –  Fatigue and reaction time (faster response) –  Fat metabolism –  All types of performance • Risks of caffeine • Nervousness, tremors, insomnia • Headache • GI problems

  18. Pharmacological Agents:Diuretics • Diuretic clinical uses • Increase urine production to reduce body water • Control hypertension, edema • Proposed benefits of diuretics • Weight control • Dilute other banned substances in urine samples

  19. Pharmacological Agents:Diuretics • Proven effects of diuretics • Significant temporary weight loss • Resulting dehydration is ergolytic –  Plasma volume   Qmax   VO2max • Risks of diuretics • Impaired thermoregulation • Electrolyte imbalance (including hyponatremia) • Death

  20. Pharmacological Agents:Recreational Drugs • Alcohol, cocaine, marijuana, nicotine • No ergogenic effects • Many ergolytic effects • Alcohol + caffeine = ergolytic effects

  21. Hormonal Agents:Anabolic Steroids • Anabolic steroid use • Androgenic: similar to male sex hormones • Enhances anabolic function (builds bone, muscle) • Athletes have become good at avoiding detection • Proposed benefits of anabolic steroids • Increased fat-free mass (FFM), strength • Reduced fat mass • Facilitate recovery after exhaustive exercise

  22. Hormonal Agents:Anabolic Steroids • Proven effects on muscle mass, strength –  body mass, FFM –  Fat mass –  Total body potassium and nitrogen (FFM markers) –  Muscle size, strength • Dose threshold for anabolic effects • Small doses ineffective • Large, chronic doses very effective

  23. Figure 16.2

  24. Figure 16.3

  25. Hormonal Agents:Anabolic Steroids • High-dose testosterone  same effects –  FFM –  Triceps and quadriceps area –  Strength • Muscle mass increase is dose dependent –  Type I and type II cross-sectional area –  Number of muscle fiber nuclei

  26. Figure 16.4

  27. Hormonal Agents:Anabolic Steroids • Proven effects on cardiorespiratory endurance –  Red blood cell production and total blood volume • No effect on VO2max • Proven effects on recovery from training –  muscle fiber damage after exhaustive lifting –  Rate of protein synthesis during recovery (rats)

  28. Hormonal Agents:Anabolic Steroids • Issues with anabolic steroid use • Moral and ethical concerns • Fair competition (basis for World Anti-Doping Code) • Sexual risks • Men: early growth stoppage, supression of normal hormones (testicular abnormalities), excess estrogen (breast enlargement) • Women: disrupted menstruation/ovulation, development of masculine sex characteristics

  29. Hormonal Agents:Anabolic Steroids • Cancer risks: prostate, liver • Cardiovascular risks • Cardiac hypertrophy, cardiomyopathy, heart attack • Thrombosis, arrhythmia, hypertension –  HDL,  LDL

  30. Hormonal Agents:Anabolic Steroids • Emotional and psychological risks –  Aggression (“roid rage”) –  Violence • Potential drug dependence • Other risks • Contracting hepatitis, HIV/AIDS –  Life span (mice) –  Incidence of birth defects • Long-term effects of abuse unknown

  31. Hormonal Agents:Andro, DHEA • Baseball steroids scandal • Androstenedione (Mark McGwire) purported to enhance testosterone production • DHEA may enhance androstenedione, testosterone • Studies generally show andro and DHEA ineffective • No significant strength gains • Possible increase in estrogen • Banned anabolic steroids more effective, popular

  32. Hormonal Agents:Human Growth Hormone • Human growth hormone (hGH) • Six proposed benefits of hGH use • Stimulates protein, nucleic acid synthesis • Stimulates bone growth (young athletes) • Stimulates IGF-1 synthesis –  FFA mobilization,  fat mass –  Blood glucose levels • Enhances healing after injury

  33. Hormonal Agents:Human Growth Hormone • Proven effects of hGH use –  Fat mass • Young athletes: no anabolic effects • Older men:  FFM,  bone density • Risks of hGH use • Acromegaly • Cardiomyopathy, hypertension • Glucose intolerance/diabetes

  34. Physiological Agents • Using any substance that occurs naturally in body to improve performance • Five major physiological agents • Blood doping • Erythropoietin (EPO) • O2 supplementation • Bicarbonate loading • Phosphate loading

  35. Physiological Agents:Blood Doping • Blood doping • Any means by which red blood cell count increases • Often through transfusion of previously donated red blood cells • Proposed benefits of blood doping • Enhanced oxygen-carrying capacity • Improved aerobic endurance and performance • Proven effects of blood doping – VO2max (long term) –  Aerobic endurance (short term)

  36. Figure 16.5

  37. Physiological Agents:Blood Doping • Maximizing benefits of blood doping • Must reinfuse 900+ ml whole blood • Must wait 5 to 6 weeks before reinfusion • Must freeze (not refrigerate) stored blood • Blood doping and endurance performance • Enhances aerobic performance • Benefit more evident in second half of race

  38. Figure 16.6

  39. Physiological Agents:Blood Doping • Risks of blood doping • Blood becomes too viscous • Excessive clotting, heart failure • Some sports set hematocrit limits for competition • Blood matching complications • Exposure to bloodborne diseases • Potential medical risks far outweigh benefits

  40. Physiological Agents:EPO • EPO slightly different from blood doping • Natural kidney hormone • Stimulates red blood cell production • Proposed benefits of EPO • Increased hematocrit • Increased oxygen-carrying capacity • Proven effects of EPO –  Hemoglobin, hematocrit, and VO2max –  Time to exhaustion

  41. Physiological Agents:EPO • Risks of EPO use • Dangerous increase in blood viscosity • Blood clots, heart attack, heart failure, stroke • Pulmonary embolism, hypertension • Effects of EPO less predictable than those of red blood cell reinfusion

  42. Physiological Agents:O2 Supplementation • Proposed benefits of O2 supplementation • Increase dissolved oxygen in blood • Delay fatigue, speed recovery • Proven effects of O2 supplementation • Preexercise treatment  little or no effect • During exercise   work, work rate, metabolic efficiency,  peak blood lactate levels • After exercise  no effect

  43. Physiological Agents:O2 Supplementation • Risks of O2 supplementation • No known risks • Safety needs further research • Oxygen equipment potentially dangerous • Overall, simply not practical

  44. Physiological Agents:Bicarbonate Loading • Proposed benefits of bicarbonate loading • Increased blood pH and buffering capacity • Delayed onset of anaerobic fatigue • Proven effects of bicarbonate loading • 300 mg/kg   all-out performance for 1 to 7 min • Enhanced H+ removal from muscle fibers • Risks of bicarbonate loading • GI discomfort (bloating, cramping) • Sodium citrate  similar results without risks

  45. Figure 16.7

  46. Physiological Agents:Phosphate Loading • Proposed benefits of phosphate loading • Enhanced PCr resynthesis • Enhanced oxidative phosphorylation • Greater O2 unloading at muscle • Proven effects of phosphate loading • Findings equivocal • Some studies no effects, others V̇O2max and time to exhaustion • No known risks of phosphate loading

  47. Nutritional Agents:Amino Acids • L-tryptophan • Proposed effects: analgesic, delays fatigue • Proven effects: no improvement • Branched-chain amino acids (BCAAs) • Proposed effects: delay fatigue – Study showed no effect from  or  BCAAs • HMB (leucine metabolite) – Some evidence may  FFM, strength but unclear – Decreases cholesterol, LDL, blood pressure

  48. Figure 16.8

  49. Nutritional Agents:L-Carnitine • Proposed benefits of L-carnitine • Enhanced fatty acid oxidation • Glycogen sparing • Proven effects of L-carnitine • Conflicting results • Most findings negative

  50. Nutritional Agents:Creatine • Creatine • Widespread use (recreational to professional) • Target: skeletal muscle • Proposed benefits of creatine • Increased muscle PCr content • Enhanced peak power production • Serves as buffer, helps regulate pH balance • Enhanced oxidative metabolic pathways

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