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Resistance Training & Hormones

  1. Jul 12, 2011 #1
    Can someone please explain to me how resistance training affects hormones? And what effects insulin has on the body post-exercise? Thanks!
     
  2. jcsd
  3. Jul 12, 2011 #2
    It's a complex subject which this article summarizes fairly well. Insulin levels, like most hormonal responses, vary according the body's demands and will decline rapidly during rest after exercise in healthy individuals (provided you don't eat anything during that time).

    http://www.unm.edu/~lkravitz/Article folder/growthhormone.html
     
    Last edited: Jul 12, 2011
  4. Jul 12, 2011 #3
    I've already read the article- it mainly relays the releases of hormones in exercising women. I was thinking more along the lines of this:

    After a workout, your body levels of GH, testosterone, and cortisol increase. This puts the body in a more catabolic state. The body needs energy so its using glucose by breaking down glycogen and fatty acids for energy. Now if you take in carbohydrate, your insulin level will increase. Does this increase of insulin inhibit any of the above hormones. I know increased levels of insulin will inhibit glucagon. What does it do to GH? Testosterone?
     
  5. Jul 12, 2011 #4

    Evo

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  6. Jul 12, 2011 #5
    Glucagon is released in response to low blood sugar and inhibited by high blood sugar, while insulin is released in response to high blood sugar and inhibited by low blood sugar, however I'm not aware they directly inhibit each other. Do you have a reference for direct interaction between the two?

    I think you're asking about the role of nutritional supplements after exercise to achieve an anabolic effect. Supplements keep insulin levels high which promotes uptake of glucose by cells. It also tends to maintain high growth hormone levels as well as possibly insulin-like-growth factor-one (IGF-1). It may lower serum testosterone levels by promoting uptake by striated muscle cells. There is some controversy about "body building" medicine. The following article cites published references.

    http://grfx.cstv.com/photos/schools/conn/genrel/auto_pdf/InsulinProject.pdf
     
  7. Jul 12, 2011 #6
    GH and test are not catabolic, they are anabolic. as is insulin(do not play around with insulin, you will kill yourself easily). as for cortisol, you will notice from evo's first link that the effect is dose-dependent. the lower-repetition scheme used there is the more anabolic of the two.

    if you want a more anabolic response, then by all means, try something with protein and carbs like chocolate milk after exercise. this is the proper way to get the insulin response. and GH and test and insulin are hardly anabolic without having the proper nutrients.

    http://www.ncbi.nlm.nih.gov/pubmed?term=chocolate milk exercise

    i can't remember if insulin has an effect on cortisol. i suspect it will lower it, but that is just a guess. if it does, that's not really a bad thing.
     
  8. Jul 12, 2011 #7
    After reading a few of the articles posted, it seems that an insulin spike due to a carbohydrate-protein supplement inhibits cortisol levels and testosterone. While on the other hand, the supplement increases IGF- which is important for muscle and bone regeneration.

    Can anyone explain why testosterone is inhibited? Is it beneficial to have testosterone levels stay elevated (because it increases muscle growth) or is it better to take in the carb-protein supplement, have testosterone level decrease, and have the IGF1 levels increase for overall muscle hypertrophy? Thanks!
     
  9. Jul 12, 2011 #8
    According to the review article in my previous post (Dudley), blood levels of testosterone are decreased with insulin spikes. This is not the same as inhibition. The reason is apparently unknown, but it's thought the reason is that testosterone is taken up by striated (skeletal) muscle. Insulin also increases the stores of muscle glycogen.

    Cortisol is released during the stress of heavy exercise and inhibits the effect of insulin on the cell membrane re glucose transport into the cells. This raises blood glucose levels and promotes gluconeogenesis. I'm not aware that insulin directly counteracts the effect of cortisol, but insulin spikes would tend to overcome the effect of cortisol on cell membranes re glucose uptake by cells. During rest after exercise, I would expect cortisol levels to drop, but I'm not sure how fast.

    Note that persistently high insulin levels can have negative effects on the kidneys, nervous system and other tissues.
     
    Last edited: Jul 12, 2011
  10. Jul 12, 2011 #9

    Evo

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    Sorry, what peer reviewed journal was that in? It appears not to be a valid reference.
     
  11. Jul 12, 2011 #10
    It cited published articles. I'm not aware of any significant errors but I don't advocate "body building" medicine. I couldn't find any published articles that directly addressed all the questions raised by the OP. I'll find an appropriate article that addresses that specific question and post it.
     
    Last edited: Jul 12, 2011
  12. Jul 12, 2011 #11
    http://jcem.endojournals.org/content/80/2/654.abstract

    This trial supports the hypothesis that insulin levels have a positive correlation with testosterone production, although sex hormone binding globulin (SHBG) appears to be inhibited. To the extent that insulin actually is associated with reduced plasma levels of testosterone, this remains unexplained. Since it is known that testosterone has a positive anabolic effect, particularly on skeletal muscle, uptake by skeletal muscle remains a reasonable hypothesis, but I can't point to evidence for this at this time.
     
    Last edited: Jul 12, 2011
  13. Jul 12, 2011 #12

    Evo

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    Don't worry about going that far, I just wanted to be sure the information was correct.
     
  14. Jul 12, 2011 #13
    i looked at that first article dudley referenced, and test dropped after exercise with or without supplementation. i think the largest difference may be the difference in lactate between supplementation (lower) and placebo (higher). a little hard to prove at this point, though. i can find articles showing that test production definitely increases in rats with lactate administration, but nothing so conclusive for humans.

    that other thing you referenced showed an estrogen increase with diazoxide administration. estrogen causes negative feedback in the hypothalamus to lower test.
     
  15. Jul 12, 2011 #14
    Diazoxide lowers insulin release from the islet cells of the pancreas. In this study it was used to show the effect of decreased insulin relative to testosterone compared to normal. Insulin levels and testosterone production were shown to be positively correlated. Since diazoxide was associated with increased estrogen, we would expect that normal to high insulin levels (in the absence of diazoxide) to correspond to lower estrogen levels and higher testosterone levels.
     
  16. Jul 13, 2011 #15
    Take a look at this-

    http://www.physsportsmed.org/doi/10.3810/psm.2010.10.1814.

    "Furthermore, data from our training study demonstrate that exercise-induced increases in GH and testosterone availability are not necessary for and do not enhance strength and hypertrophy adaptations. Instead, our data lead us to conclude that local mechanisms that are intrinsic to the skeletal muscle tissue performing the resistive contractions (ie, weightlifting) are predominant in stimulating anabolism."

    I'm getting contradictory bits of information about testosterone from different studies? WTF?
     
  17. Jul 13, 2011 #16
    WTF?

    Blood levels of testosterone (T), production of T and the direct effect of T on muscle mass and strength, other influences being equal, are three different questions. Your first question was very general. As far as your linked study goes, some studies done in the 80's seem to indicate similar findings; that T increased protein synthesis in muscles but did not increase fiber diameter. The effect of exercise was not always controlled.

    To really study the direct effect of T on muscle mass, exogenous T must given in high doses. This 1996 study, published in one of the most prestigious medical journals, seems to contradict both the earlier 80's studies and your study. However, it is may well be true that exercise related increased T levels alone may not increase muscle mass very much except under certain conditions, such as with weight training.

    http://ftp.mesomorphosis.com/downloads/The%20Effects%20of%20Supraphysiologic%20Doses%20of%20Testosterone%20on%20Muscle%20Size%20and%20Strength%20in%20Normal%20Men.pdf [Broken]
     
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