Performance Enhancing Substances in Endurance Events

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Performance EnhancingSubstancesin Endurance
Events

• Kevin deWeber, MD, FAAFP
• Director, Primary Care Sports Medicine Fellowship
• USUHS

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Objectives

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

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Performance Enhancing Modalities

• Mechanical
• Psychological
• Physiologic
• Nutritional
• Pharmacologic

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(No Transcript)
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Stimulants
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Stimulants

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

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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

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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

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Caffeines Proven Effects

• Increased time to fatigue in prolonged, moderate
  intensity exercise
• No effect on repeated sprints/heavy exercise

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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

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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

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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

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Caffeinated Sports Drinks

• No proven performance benefit
• 18-km run times
• Pl vs carb drink vs carb150mg caffeine
• consumed 4x in race
• Int J Sports Med 2005

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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

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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

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Stimulants - Side Effects

• Anxiety
• Dysrhythmias
• Hypertension
• Hallucinations
• Addiction
• Death

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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
• 1 cup coffee 100mg 1.5 mcg/ml in urine

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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

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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)
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Blood Doping - Side Effects

• Transfusion reactions
• Infections
• Increased viscosity of blood
• Stroke, MI, PE

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Blood Doping - regulation

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

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Beta-2-Agonists

• Physiology
• Bronchodilation, increased ventilation
• Examples albuterol, terbutaline, salmeterol

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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

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Creatine

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

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Creatine disproven effects

• Meta-analysis 2003
• No significant difference in field-based athletic
  performance (e.g. running, swimming)

X
X
X
X
X
X
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Branch JD. Int J Sports Nutr Exerc Metab June
2003
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Creatine - Side Effects

• Studies of 2-10 weeks no side efx
• Long term
• 40 non-responders

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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

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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

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Anabolic SteroidsDisproven Effects

• No effect on endurance exercise
• Males on treadmill
• Eur J Appl Physiol 2006
• VO2max in rats
• Med Sci Sports Exer 2004

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Anabolic Steroids - Side Effects

• Hepatocellular damage
• Cardiovascular disease
• Psychological disturbance
• Effects can sometimes be permanent!

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More side effects

• Men
• Acne
• Premature baldness
• Prostatic hypertrophy
• Female masculinization
• Injection complications
• Testicular atrophy
• Impotence
• Gynecomastia
• (some may be permanent)

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Nitric Oxide-releasing agents

• Physiology
• Arginine is a precursor of NO
• NO regulates BP and blood flow to organs
• Most supplements Arginine a-ketoglutarate
• Claims
• Improves pump and blood flow to muscles
• Increases strength and size
• Speeds recovery

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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

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Sodium Bicarbonate

• Mechanism buffers metabolic acidosis after
  strenuous exercise
• Proven ergogenic efx in high-intensity exercise
• 100m 200m swim
• Repeated sprints
• Repeated judo throws

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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

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Bicarbonate

• Dose 0.2 - 0.3 mg/kg
• GI side effects common

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Carbs

• Sports drink consumption
• Carbohydrate loading

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Sports Drink Consumption

• Evidence supports enhanced endurance performance
  vs water in events 60 min
• No benefit from added protein

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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

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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

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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

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Miscellaneous Losersin endurance exercise
performance

• Vitamin E and other vitamins
• Minerals Cr, Mg, Zn, Se
• L-Carnitine
• Antioxidants
• Pyruvate
• Arginine
• Hydroxy-methyl-butyrate (HMB)

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Anti Doping in Elite Athletic Competition

• Permitted/Prohibited?
• http//www.usantidoping.org.dro
• 1-800-233-0393

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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

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No substitute for hard work
Questions?
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Thank You!