Cheating in Sports: The Biology of Anabolic Steroids

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Cheating in SportsThe Biology of Anabolic
Steroids

• Week 2

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Definitions

• Anabolic
• Androgenic
• Steroid
• Anabolic Androgenic Steroid (AAS)

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Testosterone-Derivatives Versus Testosterone

• More specific for particular muscle development
• More anabolic and less androgenic
• Less detectable
• Minimize side-effects
• Delivery
• Longer-lived
• Slow rate of inactivation
• Decrease aromatization to estradiol
• Binds androgenic receptor better

(from Kuhn Review)
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Biochemistry of Steroid Hormones
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What is the Central Dogma of Biology?

• DNA to RNA to Protein
• Genotype Environment Phenotype

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Molecular Mechanism of Action of AAS

• Binds AR (androgen receptor), and activated AR
  turns on a number of genes
• More information available on the Nuclear
  Receptor Signaling Atlas http//www.nursa.org/fla
  sh/gene/nuclearreceptor/start.html

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How Do AAS Increase Strength and Muscle Mass?
(Wikipedia)
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Fast-Twitch (Type II) versus Slow-Twitch (Type I)
Skeletal Muscle Fibers

• Fast-twitch contract faster and with greater
  force
• Fast-twitch (anaerobic, short burst, white meat)
• Larger in diameter
• More energy reserves (e.g. ATP,
  creatine-phosphate)
• Slow-twitch (aerobic, endurance, red meat)
• More mitochondria
• Myoglobin
• More capillaries
• Is the ratio of fast-twitch to slow-twitch
  genetically determined or does it arise through
  training?

(from Guyton)
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Stacking?

• Stacking use multiple AAS at a time
• More results
• Minimize side-effects
• Minimize detection
• Delivery and target in the body
• Turn on different genes
• Different lifetimes

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Steroid Cycle

• 4 to 12 weeks
• Then 4 to 6 weeks to clear the system
• Exogenous testosterone suppresses endogenous
  synthesis may become dependent
• Total annual AAS was less than 6 months for many
  users
• How long do the effects last?

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Presentation Pointers

• Understanding
• Make sure you understand what you present
• Clarity
• What is your point?
• Logical explanation
• Keep things simple
• Fun
• Personal aesthetic
• Practice, practice, practice