stre&cond: chapter 12 - performance enhancing substances and methods

dietary supplements

highly refined products designed to add to your diet, not replace food

• NO positive nutritional value

• cannot be advertised for use as conventional food/replacing an entire diet — must be explicitly labeled

• do NOT go through FDA approval like food or drugs — uncertainty of its contents

• contains 1+: vitamin, mineral, herb/botanical, amino acid

  • concentrate, metabolite, constituent, extract, or combo

• dietary substance used by increasing total dietary intake

• HUGE market, many make unsubstantiated claims on efficacy, and do not contain listed supplement

mimicking drugs

substances that act similarly to a naturally occuring hormone and change the body’s structure or function

• stimulate hormone secretion

• influence physiological processes

• requires FDA approval for safety and effectiveness

• endogenously produced + synthetic alternative = enhance performance

  • anabolic steroids, prohormones, sarms and peptides, HCG, b-adrenergic agonists

anabolic steroids

synthetic derivatives of testosterone for longer-lasting effects of increasing protein synthesis

• TE rapidly metabolized, used medically to raise normal levels of someone with low levels

• TE → increases protein synthesis → increased muscle CSA, FFM, strength = athletic performance

• performance misuse involves higher exposure

• appeals to athletes: trained athletes accelerate gains by 2-3x since it was already hard

  • BANNED athletes: performance benefit vs those who don’t take it

  • increases in FFM can remain after stopping, continued training to preserve adaptations

  • aesthetic changes

• dosing: cycling (use/no use), stacking to produce additive effect

  • external steroids can downregulate body’s TE production

anabolic steroid effects

psych effects:

• aggression, arousal, irritability — others overstated to stop individuals from using

• hormonal disruption from cycling → depression

adverse effects/withdrawal: vary greatly between individuals

• can be reversed by not consuming anymore

• can use other drugs to reverse effects — effects resolve depend on duration of use

prohormones

precursors to the synthesis of other hormones, such as testosterone

• increases body’s ability to produce the specific hormone

• BANNED: anabolic steroid control act

  • can increase estrogen-related compounds and downregulation of body’s own TE synthesis

  • little to no improvement in performance

  • unfavorable changes in blood lipids → increase CVD

sarms

selective androgen receptor modulators: tissue-selective agonists of androgen receptors

• reduced unwanted androgenic effects in other tissues

• similar anabolic properties as anabolic steroid

• gain benefits of anabolics but reversed adverse effects

• currently NOT FDA approved

• effiicacy: improvements in lean mass, but dose-dependent — higher dose = greater effects

  • coincided with suppression of total TE, SHBG, HDL-C, triglycerides

peptides

short chain of amino acids that regulate cellular function and processes

• similarly purported to have potential for selective agonism and reduced adverse affects (like sarms)

• efficacy: clinical trials showed older adults have increases in bone turnover and free fat mass

  • terminated early due to safety related to increase congestive heart failure

HCG

found in placenta of pregnant women and can increase TE in males by mimicking luteinizing hormone

• this + anabolic steroid = restore natural TE production — bc anabolics suppress endogenous production

• little adverse effects besides injection — pain, swelling, tenderness

• sometimes administered as weight loss agent

  • NO evidence

  • likely due to caloric restriction

b adrenergic agonists

chemically related to epinephrine and can increase lean mass and reduce body fat

• lipolysis and increased thermogenesis

• initially treated asthma — clenbuterol: bronchodilator and widely abused for performance → BANNED

• repeated exposure = its receptors downregulate and cells less responsive

  • anectodical reports of tachycardia, hyperthermia, palpitations, tremors

essential AAs

dietary supplement should contain leucine since not produced by the body

• aka branched chain

• leucine: key AA for stimulating muscle protein synthesis in healthy subjects

• not known adverse effects

• expensive and dont include other kinds so just use whey protein

arginine

dietary supplement responsible for synthesis/metabolism of creatine and protein

• an essential AA commonly mixed in pre-workout

• claims: increase nitric oxide levels (vasodilation/blood flow) → increased performance

  • NO effect

• adverse effects > 13 g, cramping, GI problems

HMB

dietary supplement used to reduce muscle protein breakdown by inihibiting ubiquitin protease pathway

• a derivative of EAA leucine

• preserves muscle

• in untrained: may reduce muscle atrophy during bed rest

  • improvements in strength and lean body mass with training

• in trained: may improve strength and lean body mass gains as adequate training stimulus is provided — higher volume = higher intensity

• no known adverse effects

b alanine

dietary supplement that works as a nutritional muscle buffer and improves buffering capacity

• non essential amino acid

• rate limiting substrate for carnosine synthesis → muscle buffering of H+

• improve anaerobic performance: events > 60 sec, repeated high INT bouts

• must be taken consistently over time for effect

• adverse effects: paresthesia — skin tingling, numbing

creatine

dietary supplement used to increase muscle creatine content (20%) and effect of phosphagen system

• produced in liver and stored in skeletal muscle (90%)

• saturation limit: maintain 2-5g a day — already high and additional increase → no response

• benefits strength, sprinter, power athletes: increase PCr stores → faster ATP generation → more ATP available → increase max strength and power

• increase FFM → intracellular water → more weight gain due to water pulled into muscle

• cognitive benefit: during high stress

• adverse effects: GI discomfort, kidney stress

caffeine

dietary supplement used as CNS stimulant and increase alertness

• coffee, energy drinks, pre-workout, tablets etc.

  • purified caffeine more predictable dose than drink

  • ~9mg/kg max dose

• aerobic endurance: can increase time to exhaustion by increasing fat oxidation → reduced glycogen depletion

• anaerobic high INT: can increase strength, power, and repeated high INT performance

  • can enhance neuromuscular activation and excitation contraction coupling

• adverse effects: anxiety, GI distress, insomnia, tremors, CV effects, physical dependence

  • high quantities → increase risk of dehydration → increase risk of heat illness