I have had this conversation with people before...even at the peak of your gh production in your youth, you are not going to produce more than the equivalent of 0.5-1.0 iu MAX (i found some studies on this measuring gh output, google it/pubmed it) so I dont really subscribe to the idea of not using gh at night if you are young. IMO its like saying dont do a cycle of test when you are your 20s because your test is at an all time high when you would be putting way more testosterone in your bloodsteam than youd produce at any age.
I think why it's recommended for older guys to pin at nite is the body produces it's largest pulses of gh at night. It's a attempt to replicate the body's natural rhythms of hg pulses
This is a small excerpt of a paper I read
Since GH is released when you sleep, it must follow that SLEEP is also critical to every athlete. Many elite athletes are known to take naps during the day between work-outs. This not only provides them with additional rest, but it also increases GH secretion. Of course it is unrealistic for most working athletes to be able to take naps (unless you live and work in a region that practices the
siesta), therefore getting adequate sleep must be a major priority. Sacrificing sleep results in sacrificing release of growth hormone which leads to inadequate recovery. This becomes important when one consistently deprives the body of adequate sleep in order to wake-up to complete that early morning work-out.
Additionally, GH release is based on the body's circadian rhythms. More GH is released during the earlier hours of the night then the later hours. Thus, sleep schedules are also important as 8 hours of sleep from 10 pm to 6 am causes greater GH release than 8 hours of sleep from midnight to 8 am. The above diagram shows pulses of growth hormone corresponding to the four sleep cycles that occur during an average good night's sleep.
Exercise and physical stress also increase GH levels, however the majority of GH release occurs during sleep.
Somatotropic cells in the
anterior pituitary gland then synthesize and secrete GH in a pulsatile manner, in response to these stimuli by the hypothalamus. The largest and most predictable of these GH peaks occurs about an hour after onset of sleep with plasma levels of 13 to 72 ng/mL.[SUP]
[13][/SUP] Otherwise there is wide variation between days and individuals. Nearly fifty percent of GH secretion occurs during the third and fourth
NREM sleep stages.[SUP]
[14][/SUP] Surges of secretion during the day occur at 3- to 5-hour intervals.[SUP]
[3][/SUP] The plasma concentration of GH during these peaks may range from 5 to even 45 ng/mL.[SUP]
[15][/SUP] Between the peaks, basal GH levels are low, usually less than 5 ng/mL for most of the day and night.[SUP]
[13][/SUP] Additional analysis of the pulsatile profile of GH described in all cases less than 1 ng/ml for basal levels while maximum peaks were situated around 10-20 ng/mL.[SUP]
[16][/SUP][SUP]
[17][/SUP]
A number of factors are known to affect GH secretion, such as age, sex, diet, exercise, stress, and other hormones.[SUP]
[3][/SUP] Young adolescents secrete GH at the rate of about 700 μg/day, while healthy adults secrete GH at the rate of about 400 μg/day.[SUP]
[18][/SUP] Sleep deprivation generally suppresses GH release, particularly after early adulthood.[SUP]
[19][/SUP]
Stimulators of growth hormone (GH) secretion include: