10-06-2012, 01:42 PM #1
- Join Date
- May 2002
- M-Chem Coin = $1
- Rep Power
Growth Hormone and fat loss. Connective Tissue. Insulin Resistance
Growth Hormone (GH) Release and fat loss Ė Q&A
by Lyle McDonald
On Tuesday of last week I ran a research review on casein Hydrolysate and Anabolic Hormones and Growth looking at two papers, one of which was a paper showing that the acute hormonal response (in terms of testosterone and growth hormone) to weight training had zero impact on growth. In the comments section, at least three different people asked a semi-related question that Iíve reproduced below and which I want to address in some detail today.
Question: A common recommendation bandied about by trainers is to place any LISS cardio after ďlactate trainingĒ or whatever they choose to call higher intensity work, and they say that if fat loss is the aim, this will milk every last bit of effectiveness out of the low intensity work (versus keeping it a separate session entirely). And they usually say that increased lactate leads to increased GH, leads to increased lipolysis, so that when the low intensity work comes after the much higher intensity work, you oxidize more of the fat they claim gets mobilized. So does this pairing of LISS cardio after high(er)-intensity work still make it at least somewhat more effective (from a fat-loss standpoint) than when performed separately? And if so, is it more due to other things you mentioned (glycogen depletion, effect of the catecholamines, etc.), so that the intended effect is the same, it was just the purported reason for the effect that most of these trainers had wrong (namely implicating a GH-induced increase in lipolysis as the reason)?
Answer: Thereís no doubt that growth hormone (GH) is involved in lipolysis although, compared to hormones such as insulin and the catecholamines (epinephrine/norepinephrine aka adrenaline/noradrenaline) it plays a distinctly secondary role. There are other hormones of course, testosterone, estrogen, progesterone, Interleukin-6 and a new player called atrial-natriurietic peptide (ANP) all play a role as well. Here Iím only going to talk about GH.
First let me define a single term which is lipolysis. This refers to the breakdown of stored fat (technically: triglycerides) in fat cells for release into the bloodstream. While there are more steps involved in losing fat (and the specific pathways are all discussed in some detail in The Stubborn Fat Solution), clearly if you canít get the fat out of the cell in the first place, little else matters. Lipolysis simply refers to that process, whereby fatty acids stored within fat cells are broken down to be released into the bloodstream, hopefully to be burned elsewhere in the body (generally skeletal muscle or liver).
For example, while studies of injectable GH have generally crapped out in terms of muscle growth (there is an increase in lean body mass but itís primarily water and connective tissue, not actual muscle mass), it has shown impact on fat loss. As well, the nighttime GH pulse has been shown to be important for lipolysis the next day. Finally, during periods of fasting or even low-carbohydrate diets, studies clearly show that blocking the normal GH response not only limits lipolysis, but this ends up increasing muscle loss (because the body doesnít have fatty acids to burn).
So far so good right?
Add to that a host of studies done primarily during in the 80ís by William Kraemer and his group showing that certain training protocols (notably higher reps and short rest periods; 3X10 with 1′ rest was typically used) elevate GH and you can see where folks got the idea that training in this fashion would be good for fat loss.
I think the first place I saw this idea floated was Charles Poliquinís original German Body Composition Training. Claimed to be based on German research into the hormonal response to training, it was based arund multiple sets of high reps with short-rest, the premise of which being to raise GH (and lactate production during training seemed to be involved somehow) to increase fat loss.
More specifically to todayís question, many trainers will use that type of training (using various permutations of Metabolic Training, discussed in some detail in Weight Training for fat loss Part 1 and Weight Training for fat loss part 2) to be followed up by low-intensity cardio. The idea being that the GH response will promote lipolysis and the low-intensity cardio will then Ďburn off the fatty acidsí.
And hereís we run into the problem with the idea: the time course. Because while GH is certainly involved in lipolysis, itís effects are pretty slow to occur. Cutting ot the chase, after a big GH pulse, you donít really see a big increase in lipolysis or blood fatty acids until about the 2 hour mark. Which means that a protocol based around the idea of elevating GH during the intense portion so that cardio done a few minutes after will burn off the fatty acids mobilized by the GH pulse is fundamentally incorrect from a physiological point of view.
But that doesnít mean it doesnít work. Quite in fact, the premise is still fairly sound, this is just a place where Iím being picky about the mechanism. As discussed in Weight Training for fat loss Part 1 this type of training still has metabolic effects that can be conducive to fat loss (even acutely), they simply arenít related to the GH pulse in any form or fashion.
Rather, increases in epinephrine/norepinhrine will have a much stronger acute effect on fat mobilization, and the glycogen depletion due to this type of training tends to enhance fat oxidation in skeletal muscle. Quite in fact, the two advanced protocols in my Stubborn Fat Solution are at least superficially similar to this type of training, high-intensity work followed by low-intensity work. But GH isnít the mechanism behind it.
So bascially, what the person asking the question wrote in the second-half of his question. The combination of high-intensity followed by low-intensity work can still be effective for fat loss, itís simply not for the mechanism stated. The impact of GH on fat loss is simply too slow to be involved. Rather, other mechanisms related to hormonal response, glycogen depletion, etc. are what are involved and responsible. GH simply isnít relevant to the process in that short of a term.
Question:Lyle. Thanks for this. Iím happy you clarified this.
Does elevating GH still has some favorable effect on fat loss over long-term? Or as you said, this type of training works but itís unrelated to GH? (Iím not sure if I understood well)
And does lactate really makes GH peak? (could you point studies?)
Answer:As noted, injectable GH certainly impacts fat loss but the simple fact is that small pikes in GH due to training are unlikely to affect much of anything. As well, Iím not sure if anyone ever showed mechanistically that lactate was involved in the GH pulse. Itís simply that the same types of training that tend to raise lactate (high rep/short rest) is associated with a bigger GH pulse (compared to other types of training). Kraemer did a bunch of that work in the 80ís and 90ís.
Question: So what, if any benefit, is there from taking injectable GH (and test). Iím a 59 year old male. Iíve been lifting for about 4 years now, never having done so before, and have made some significant progress. I have VERY low blood tested levels of GH (and test, for that matter), though, and my doc (who has watched my progress and is, I think, just trying to be helpful, is suggesting I consider therapeutic dosages designed to restore GH and Test levles to the putative ďsatdĒ levels for 20 year olds.
Answer: Sort of tangential to the article. Injectable stuff does very different things than small training related spikes. Certainly testosterone replacement appears to have some benefit (in terms of helping with muscle loss issues that occur with aging, with Ďandropauseí being a new catchphrase). Of course, itís also involved in some types of cancer (e.g. prostate) so there are always pros and cons.
I think the use of GH is a bit more debatable. It certainly can reduce body fat, improves connective tissue health but it can also cause insulin resistance and other problems. For the price Iím not convinced itís that worthwhile but this is also a bit outside of my area of interest.
By big in vegas in forum Peptide HGH IGF 1 DiscussionReplies: 18Last Post: 05-11-2016, 12:18 PM
By Presser in forum Bodybuilding Steroid & Training ArticlesReplies: 8Last Post: 09-14-2014, 08:42 PM
By gambino in forum Peptide HGH IGF 1 DiscussionReplies: 2Last Post: 04-03-2014, 07:25 PM
By NAIR in forum Peptide HGH IGF 1 DiscussionReplies: 3Last Post: 10-21-2013, 04:36 PM
By Presser in forum MuscleChemistry DiscussionReplies: 13Last Post: 12-19-2008, 11:28 AM