Tag Archive for Body composition response to exogenous GH in highly conditioned adults

Body composition response to exogenous GH in highly conditioned adults

Body composition response to exogenous GH in highly conditioned adults

STUDY, demonstrating positive body composition changes in highly trained athletes w/ 2g/kg per day protein intake & 8iu of GH 3x per week (EOD), w/ no other compounds.

NOTE: Protropin 1mg = 3iu or 1iu = 333mcg
EOD dose (3x per week) in the following study: 2.67mg or 8iu
Weekly total dose = 8mg or 24iu

Summary results:
FFW = fat free Weight
FW = fat Weight

The weight results are in Kilograms not pounds.

Body composition response to exogenous GH during training in highly conditioned adults, D. M. Crist, J Appl Physiol 65: 579-584, 1988


The effects of biosynthetic methionyl-human growth hormone (met-hGH) on body composition and endogenous secretion of growth hormone (GH) and insulin-like growth factor I (IGF-I) were studied in eight well-trained exercising adults between 22 and 33 yr of age for 6 weeks.

Dosing & Administration of HGH:

The met-hGH (experimental) treatment consisted of 8.0 mg (2 U/mg) per week of methGH (Protropin; Genentech, San Francisco, CA), which was divided into three doses (2.67 mg/dose) and delivered on alternate days (3 days/wk) in 0.5 ml of bacteriostatic diluent. Because of differences in the body weights of the subjects, the relative dose range varied between 0.03 and 0.05 mg/kg per injection. Injections were given between 0800 and 1500, and their delivery was rotated among four to six sites throughout the study period. Treatments were administered on a double-blind basis with neither the experimental subject nor the person administering the injections knowing which treatment was being delivered. The total weekly dose of met-hGH used in this study (8.0 mg) was considered supraphysiological, since the spontaneous release of human GH during a 24-h period is purportedly -0.68 mg (4.8 mg/wk) in men and 0.79 mg (5.5 mg/wk) in women (30), similar to amounts reported by others (6).


In the present study, we found that alternate-day treatment with met-hGH altered body composition in highly conditioned, exercising adults by increasing FFW (fat free weight), decreasing %fat, and increasing FFW (fat free weight)/FW (fat weight). These changes were significantly greater than those produced by exercise alone.

Moreover we found that supraphysiological amounts of met-hGH were sufficient to significantly elevate circulating concentrations of IGF-I in all our subjects, confirming that the changes in body composition were indeed due to real alterations produced in vivo by the hormone treatment.

Suppression of endogenous HGH

It has been reported previously that exogenous GH will suppress endogenous release of the hormone (19,23) and that this effect may be mediated in part by elevated levels of IGF-I (23). On a preliminary basis, we found that treatment for 6 wk with supraphysiological doses of met-hGH produced an impaired endogenous GH response to stimulation in some, but not all, of our subjects. This variable response may be related to the amount of hormone used in the study. Although a significant group elevation in IGF-I levels occurred during the met-hGH treatment, this response was still below the upper limit of normal (2.20 U/ml) for the study group. Thus it is plausible that the treatment dose of met-hGH used and the subsequent moderate increase in IGF-I levels led to feedback suppression of endogenous GH release in five of the seven subjects measured for this effect, whereas these physiological events were insufficient to produce this effect in two of the subjects.

Intense exercise increases sensitivity to HGH??

…One possible explanation for the disparity between our findings and those of others (25, 26) is that the stress of long-term, intensive exercise training could induce alterations in vivo, which might potentiate tissue sensitivity to the physiological actions of GH (2). In any case, it is clear from our findings that supraphysiological doses of met-hGH increased circulating concentrations of IGF-I and increased FFW (fat free weight) and decreased FW (fat weight) in highly conditioned, exercising adults.

Soft-tissue Overgrowth?

There are two principal adverse reactions associated with excessive amounts of human GH, carbohydrate intolerance, and soft-tissue overgrowth. In the present study, we measured fasting blood glucose levels periodically throughout each treatment and found no real changes suggestive of a hyperglycemic response to methGH. Because soft-tissue overgrowth is associated with abnormally high levels of IGF-I, the normal responses observed suggest that the chance for soft-tissue overgrowth occurring in our subjects was minimal. However, it is unreasonable to conclude that use of met-hGH is safe as an adjunct to exercise in healthy adults until more subjects are studied over longer periods of time and with more stringent tests for detecting changes in glucose tolerance and soft-tissue overgrowth.

Diet used

To avoid compromising the dietary requirements for optimal tissue anabolism during the met-hGH treatment, our subjects ingested between 2.05 and 2.10 g/kg a day of protein and a minimum number of kilocalories to maintain body weight. The kilocaloric requirement removed the potential bias from a dietary-induced FW loss.

In Conclusion

We conclude that treatment with supraphysiological doses of met-hGH will significantly alter body composition in adults who are highly conditioned from years of exercise training. The magnitude of this effect, however, is dependent in part on the amount of hormone given per body weight of the individual rather than endogenous GH secretory status. Changes in body composition are directly related to met-hGH administration, but the manifestations of treatment may be mediated in part by increased production of IGF-I or other GH-dependent serum anabolic factors. Moreover, supraphysiological treatment with met-hGH in exercising adults may produce impairments in the stimulated release of endogenous GH in some individuals.

The above study is one of those rare studies that is directly applicable to bodybuilding. One to add to your knowledge base.

Things to note:

- GH w/o exogenous anabolics/androgens and w/o insulin increased muscle mass and lowered bodyfat % over 6 weeks.

- The participants were healthy young women & men.

- Participants were highly trained athletes who had no expectation of losing body weight nor gaining bodyweight because these parameters were stable due to their current conditioning.

- The dosing was every other day, only 3x per week.

- The daily dosing was 8iu for a weekly total of 24iu.

- This was sufficient to elevate IGF-1 levels but not to the point where they contributed to soft-tissue growth.

- No soft-tissue growth (such as gut) occurred.

- Protein intake was 2g/kg but diet was maintenance (body recomposition on a maintenance diet).

- IGF-1 was underscored as the primary suppressant of natural GH release and it was at a level where after 6 weeks five of the seven participants had suppressed natural GH release.

- the study’s estimation of what the normal level of GH is in men & women is too high because the study was done in 1988 when assays were not sensitive enough to distinguish between GH ligands, GH-binding protein and GH fragments. (This has no effect on the results …just a note not to rely on their stated estimate in that regard.)

What can you (and I too of course) learn from this, that goes against convention?

“GH is not anabolic w/o insulin” does not mean that you need exogenous insulin.

A sufficient amino acid pool is likely required.

You can both gain muscle & lose fat at a maintenance caloric intake w/ GH & training.

Six weeks is a sufficient amount of time to make positive changes.

You don’t need beaucoup amounts of GH!!!!


Share with your friendsEmail this to someoneTweet about this on TwitterShare on Google+Share on FacebookPin on PinterestDigg thisShare on StumbleUponShare on TumblrShare on Reddit
eXTReMe Tracker