The secretion of GH is controlled by many variables such as food intake, exercise, sleep and stress, and by other factors such as age, body mass, and gender. Exercise is known to be a
significant stimulus of GH secretion. Most important, GH secretion is affected profoundly by the circadian clock - as you will soon read, factors such as hunger and physical stress
experienced during the day, and deep sleep at night, can up regulate, i.e. stimulate, GH release. GH blood levels are characterized by large pulses, or releases, of GH succeeded by very
low-level pulses. The largest pulse occurs during deep sleep, which for most people normally begins one to two hours after the onset of nighttime sleep.
Sleep deprivation, chronic stress, or poor eating habits can adversely affect GH secretion. A GH deficiency can lead to an abnormal level of bodyfat, a decrease in exercise endurance,
poor health, reduced bone mineral density, impaired lipid (fat) metabolism, stunted growth, and advanced aging. By manipulating certain daily feeding and sleeping cycles, and in
conjunction with special weight-training routines, you may very well be able to enhance significantly the actions of GH.
Growth Hormone (GH)
GH, also known as somatotropin, is a poly-peptide hormone that is secreted by cells in the anterior pituitary gland. (Peptides are constituents of protein; the protein molecule is split
into such parts during digestion.) The main effects of GH are stimulation of bone growth, anabolic effect in the muscles, conservation of protein and carbohydrates, and lipolysis, i.e.
mobilization of fat for energy. The effects of GH are partly enforced by mediators, of which the most important are insulin-like growth factors IGF-1 and IGF-2. IGF-1, for example,
promotes tissue growth and the health of the body's organs.
As noted above, an inner circadian rhythm controls GH secretion. GH secretion starts to decline during the fourth decade of life. Important to note is that aging will cause diminished
GH secretion during the day, but the sleep-associated GH pulse persists longer and will decline more slowly over time. Thus any method that can help increase GH release during the day
may have a profound anti-aging, as well as an anabolic, effect on the body.
Regulation of GH
GH release is regulated by stimulating and inhibitory agents. The hypothalamus regulates metabolism by exercising influence on the functioning of the pituitary gland. Two hypothalamic
peptides control secretion of GH. Growth hormone releasing hormone (GHRH), which causes the release of GH from the pituitary gland, increases its secretion when the GH plasma level drops.
Somatostatin, which inhibits GH secretion, increases its secretion when the GH level increases.
Somatostatin is widely distributed in the body. Any method that suppresses somatostatin would help stimulate GH release and thereby enhance overall growth and fat loss.
Feeding Cycles and GH
Food intake is an important influencing factor in fat burning and the rate of growth. Mammals feedings are controlled by an innate biological mechanism that involves the regulation of
hormones and feelings of hunger, aggression and satiety. Animals and humans eat to satisfy their immediate energy and nutritional needs. Regulation of food intake involves the sensation of
factors such as food availability, danger or temperature. Under certain conditions such as lack of food or danger, human survival depends on the ability to cycle between periods of sustaining
life (with minimal food intake) and periods of overeating, while allowing energy and nutrients to be stored anabolically in anticipation of high energy demands.
Animal and human feeding cycles are therefore primarily controlled by a survival-related mechanism. Catabolism is the reverse of anabolism. When facing catabolic-inducing conditions such as
fasting, undereating or intense physical stress, the body triggers its survival mechanism, thus activating very powerful anabolic-stimulating factors to compensate and adapt. The brain plays
a key role in regulating growth and feeding cycles. Experiments done in the 1940's showed that certain lesions in the hypothalamus reduce feeding whereas other lesions induce overeating. The
results led to the hypothesis that various lesions in the hypothalamus are preprogrammed to control feeding cycles of undereating and overeating through sensations of satiety and hunger.
Recent biological studies reveal a more sophisticated neural control of feeding and energy balance. A large number of neuropeptides, which are used as primary or co-transmitters in nerve cells,
were found to exert either stimulatory or inhibitory effects on feeding and growth and overall energy expenditure. For instance, a lack of food will increase hunger-stimulating neuropeptides
such as neuropeptide Y (NPY) and galanin, as well as the stress hormone known as Cortisol. Among the neuropeptides in the brain, NPY is the most prevalent. NPY is a very powerful stimulator
of feeding behavior. Galanin, a chemical also found in the brain, stokes the hunger for fatty foods in particular. On the other hand, when you are eating full meals, hunger-inhibitory agents
such as the hormones leptin and insulin will normally signal the brain to sense satiety and reduce feeding.
This survival-related feeding mechanism controls various biological functions. Besides stimulating or inhibiting the amount of food eaten, neuropeptides help regulate cravings. NPY induces
a preference for carbs whereas galanin induces a preference for fat. Most important, these neuropeptides may also exert signals that promote fat burning and growth. NPY and galanin induce a
general anabolic state by stimulating GH release, thus improving energy balance and accelerating fat burning.
Hunger and Growth
Hunger involves the actions of neuropeptides that stimulate GH release. NPY and galanin are also found in the central ner- vous system and the gastrointestinal tract. Besides their effects
on feeding and energy balance, galanin and NPY are believed to increase GH secretion by inhibiting somatostatin, thus indirectly increasing GHRH secretion. As noted previously, this secretion
stimulates GH release.
How to Enhance GH Actions Practically
In summary the galanin-NPY-GH axis may play an important role in regulating feeding and overall growth. All the above information clearly indicates that the hunger sensation, with its related
neuropeptides, helps increase GH release during the day for those who fast or undereat. Human feeding cycles are controlled by a primal survival mechanism that helps sustain life under tough
external conditions such as lack of food or an intense physical stress. Therefore, undereating and hunger will activate a powerful anabolic stimulation through GH release. In turn, fat burning
will accelerate while sparing protein and carbs.
Eating at night in a relaxed state will likely close the feeding cycle. Keeping a steady daily sleep-wake cycle and avoiding sleep deprivation will help maximize the impact of GH on the body
during deep sleep. Overall, maintaining feeding cycles that also include periods of hunger and physical stress such as exercise, followed by periods of full nourishment and relaxation and
combined with sufficient amounts of sleep, will help maximize GH's anabolic and rejuvenating actions on the body. Avoid chronic calorie and carb restrictions. Carbs are necessary for effectively
finalizing GH actions.
You should take note that GH has a profound affinity for connective-tissue and bone buildup. Bodybuilders, martial artists, and other athletes more than often suffer from injuries because of
weak tendons or low bone density. Bones and connective tissue play critical roles in effective muscular development. GH helps facilitate the repair of muscle fibers and tendons, as well as the
mineralization of bones. Insufficient GH release will adversely impair overall muscle and strength gain.
Power Naps to Enhance Muscle Gain and Fat Loss
Power naps may help increase GH release during the day. GHRH and deep sleep highly affect each other. High levels of GHRH can increase the amount of deep sleep and vice versa. Low levels of GHRH
can impair slow wave sleep, the deepest stage of sleep, thus shortening sleep time with an adverse decline in GH release. Interestingly the amount of GHRH messenger RNA - messenger RNA transfers
information from DNA to the areas of the cell that are protein-forming - could be highest in the morning, in particular for those who suffer from insomnia or those who retire late. Thus, for some
people, skipping morning sleep may impair GH secretion. In these cases, taking a power nap in the afternoon is highly recommended. The body will compensate for the lack of deep sleep by inducing
deep sleep faster during the afternoon siesta and thereby increase GH release. For individuals who wish to accelerate muscle gain and fat loss, power naps may be one effective way to accomplish