Performance Enhancing Substances in Endurance Even

							      Performance Enhancing
            Substances
       in Endurance Events




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

Discuss substances used to
enhance performance in endurance
events
Discuss any medical evidence of
their safety and effectiveness
        Performance Enhancing Modalities
Mechanical
Psychological
Physiologic
Nutritional
Pharmacologic
Stimulants
                         Stimulants
Caffeine
Amphetamines
Cocaine
Sympathomimetics
–   Ephedrine
–   Pseudoephedrine
–   Phenylephrine
–   Phenylpropanolamine (PPA)
Modafinil
               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
  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
Caffeine‘s Proven Effects
Increased time to fatigue in
prolonged, moderate intensity
exercise
No effect on repeated sprints/heavy
exercise
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
   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
        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
  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
            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
             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
                 Stimulants - Side Effects

Anxiety*
Dysrhythmias*
Hypertension*
Hallucinations
Addiction
Death
                      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
                       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
              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)
                    Blood Doping - Side Effects

Transfusion reactions
Infections
Increased viscosity of blood
 – Stroke, MI, PE
             Blood Doping - regulation
Erythropoietin only by prescription
Doping banned by USADA, NCAA
Blood tested for antigens
Ceiling on allowable Hct level at 50
        Beta-2-Agonists
Physiology
– Bronchodilation, increased ventilation
– Examples: albuterol, terbutaline,
  salmeterol
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
                    Creatine
Replenishes ATP in anaerobic exercise
No federal assessment of quality,
performance, or safety
Proven to increase lean body mass, strength
Creatine – disproven effects
Meta-analysis 2003:
– No significant difference in field-based
  athletic performance (e.g. running,
  swimming)




X                       X X
    Branch JD. Int J Sports Nutr Exerc Metab June 2003
                  Creatine - Side Effects
Studies of 2-10 weeks: no side efx
Long term:
40% non-responders
                            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
             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
  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
Anabolic Steroids - Side Effects
                   Hepatocellular damage
                   Cardiovascular disease
                   Psychological disturbance

                 Effects can sometimes be
                    permanent!
                     More side effects…

Men
– Acne
– Premature baldness
– Prostatic hypertrophy
– Female masculinization
– Injection complications*
– Testicular atrophy
– Impotence*
– Gynecomastia*
(some may be permanent)
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
  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
     Sodium Bicarbonate
Mechanism: buffers metabolic
acidosis after strenuous exercise
Proven ergogenic efx in high-intensity
exercise
– 100m & 200m swim
– Repeated sprints
– Repeated judo throws
           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
    Bicarbonate
Dose: 0.2 - 0.3 mg/kg
GI side effects common
          Carbs




Sports drink consumption
Carbohydrate loading
 Sports Drink Consumption
Evidence supports enhanced
endurance performance vs water in
events >60 min
No benefit from added protein
  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
  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
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
                   Miscellaneous Losers
                   in endurance exercise performance


Vitamin E and other vitamins
Minerals: Cr, Mg, Zn, Se
L-Carnitine
Antioxidants
Pyruvate
Arginine
Hydroxy-methyl-butyrate (HMB)
          Anti Doping in
    Elite Athletic Competition



Permitted/Prohibited?

 http://www.usantidoping.org.dro
         1-800-233-0393
      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
No substitute for hard work…




           Questions?
Thank You!