Ergogenic Aids and Sport 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 Pharmacological agents Hormones Physiological agents Nutritional agents

Table 16.1

Table 16.1 (continued)

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

Figure 16.1

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)

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

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

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

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

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

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

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

Pharmacological Agents: 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

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

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

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

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

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

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

Figure 16.2

Figure 16.3

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

Figure 16.4

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)

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

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

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

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

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

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

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

Physiological Agents: 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)

Figure 16.5

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

Figure 16.6

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

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

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

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

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

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

Figure 16.7

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

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

Figure 16.8

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

Nutritional Agents: 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

Nutritional Agents: Creatine ACSM conclusions regarding creatine Enhances high-power-output activity Maximal strength not affected With resistance training  strength gains Results do not live up to expectations Creatine + exercise =  FFM, strength May not improve performance

Nutritional Agents: Contamination of Supplements Supplement marketing and labeling not overseen by FDA Purity of supplements and accuracy of supplement labels suspect Contamination with banned substances can lead to disqualification, forfeit of medals