Growth Hormone & Somatotropin are an Ergogenic Aid BPK 312 MARCH 28 2017 MICHAEL MORKOS PAUL SOURIAL DEL INGVALDSON
Table of Contents 1. Hypothesis 2. Clinical Use 3. Mechanism of Action 4. Growth hormone (GH) is an ergogenic aid 5. (GH) is not an ergogenic aid 6. Critiques of counter-point articles 7. Conclusion
Hypotheses! Point hypothesis: Growth Hormone or somatotropin is a safe ergogenic aid to increase body size by promoting protein synthesis and mobilizing lipids.! Counterpoint hypothesis: Growth Hormone or somatotropin is not a safe ergogenic aid to increase body size by promoting protein synthesis and mobilizing lipids
Normal Ergogenic Aid Use (EA)! Treats children and adults with growth deficiencies.! Used to treat GH deficiency in adults! Decreased adipose tissue, increased muscle volume (Bengtsson et al, 1993)! Used to treat Prader-Willi syndrome in children! Decreased body fat %, increased height velocity (Davies et al, 1998)
Mechanism of action! GH released from anterior pituitary! GH binds to the GH receptor (GHR)! Phosphorylation of the GHR, initiates JAK-STAT pathway! (STAT) translocates into target cell nucleus.! IGF-1 released! Increased protein synthesis in muscle tissue! Increased fat mobilization in fat tissue.
Figure from (Khan et al, 2002)
Recommended Daily Allowance! Not a nutrient, so no RDA! Recommended dose based on need and on weight! 0.013-0.026 mg/kg/d for GH deficient adults! Range with frequency of adverse effects [being] very low : 0.025 0.045 mg/kg/d
Safe use! No studies for outcomes of excessive use.! Excessive growth hormone production from pituitary! Gigantism children! Acromegaly adults! Both increase bone, hand and feet size
Point-GH on Resistance Training Healy et al. (2003) (Healy et al, 2003) Watched for 3 effects of GH: Rate of leucine appearance Non-oxidative leucine disposal (NOLD) Leucine oxidation Rate of appearance & NOLD increased Oxidation decreased
Point-Effect of GH On Body Composition Meinhardt et al. (2010) Randomized subjects to four groups. There was: Decreased fat mass Increased Lean body Mass (Meinhardt et al, 2010)
Point- GH on muscle growth in resistance training. Yarasheski et al. (1997) Studied GH effects on muscle growth Measured protein synthesis and breakdown Both increased Whole body protein synthesis rate increased Protein balance was higher in the GH (Yarasheski et al,1997)
Counter-point GH intake on protein catabolism (Goldberg, 1968) Rates of rat protein catabolism observed in: non-growing muscles muscles undergoing GH intake Overall low protein activity in rats undergoing GH intake (Goldberg, 1968)
Counterpoint - GH intake on muscle strength (Taaffe et al, 1994) Double-blind experiment 1 group received placebo Muscle strength (kg) at baseline, 14 and 24 weeks Exercise group baseline 14 weeks 24 weeks Bicep curl 1 group received GH 10 weeks of strength training Little improvement in Tricep extension Leg press muscular strength (Taaffe et al, 1994)
Counterpoint - Physiological effects of GH intake (Hoffman et al, 1996) P<0.003 Double blind study with GHdeficient adults Groups: placebo physiological dose of GH supra-physiological dose of GH Results: increased Na+ and fluid GH dose (mg/kg) (Hoffman et al, 1996) retention
Conclusion! Growth Hormone or somatotropin is a safe ergogenic aid to increase body size by promoting protein synthesis and mobilizing lipids
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