Take Your Amino Acids Before Exercise

There is debate as whether for the best anabolic gains should take Amino Acids (BCAA’s) before or after exercise. Some studies have shown its better to take BCAAs before while others have determined it does not matter when.   He is my rationale as to why it may be more important to take them before exercise.  In a recent paper written by protein synthesis guru’s Arny Ferranado and Robert Wolfe, it mentioned an interesting study involving GH and protein synthesis.  Subjects were randomly assigned to receive daily subcutaneous injections of placebo (saline) or GH. Each subject was studied in the fasted state, followed by an infusion of the same commercial amino acid formula. The results clearly demonstrated no difference in fasted net protein balance between the placebo and GH groups. The principal effect of GH was realized when combined with Amino Acids, as there was a clear anabolic effect²².  Based on the study, only when GH is in the presence of Amino Acids is their anabolic effect.  See me point? Back in 1998, Dr. Kraemer did an interesting study where they looked at post-exercise GH responses in response to weight trainers that took a protein based supplement before exercise for three consecutive days and compared them to those that ingested just water.  Serum GH concentrations significantly increased immediately postexercise and returned to resting concentrations by 60 min of recovery in both groups. On day 1, GH concentrations at 0, 15, and 30 min postexercise were significantly higher in the group consuming the protein supplement compared to placebo³³. Finally, several Amino Acids have been shown to increase serum GH concentrations, including the BCAA leucine.  It make sense to take Amino Acids just before a GH peak that occurs with exercise to facilitate the greatest anabolic effect compared to post exercise when hormone are declining.      

The GH Preferentially Burns Abdominal Adipose Tissue

An interesting phenomenon about GH is that it stimulates adipose tissue fat mobilization after a delay of approximately 2 hours³.   During sleep, the peaks in GH result in maximal levels of free fatty acids about 120 minutes later⁹.  Additionally, GH increases circulating levels of glycerol and free fatty acids in GH deficient men after a lag time of 2-3 hours¹². So if you are trying to get ripped up, is one little peak in GH during your workout going to make that big of a difference in your physique?  Your damn right it does…Researchers took subjects and gave them a dose of GH but kept it in the physiological range; a single GH spike increased fat mobilization in femoral (thigh) and abdominal adipose tissue, the greatest increases being more prominent in the abdomen. The more pronounced effect of fat mobilization in abdominal adipose tissue may be the reason why GH deficient men look like they are pregnant and hold most of their fat in their stomach.  The lipolytic response is two- to threefold more pronounce in the abdomen; the effects of GH will lead to preferential loss of abdominal subcutaneous fat¹⁰. When obese men are administered GH the fat seems to just melt off.  For example, thirty men, with abdominal/visceral obesity were treated with recombinant human GH in a 9-month randomized, double-blind, placebo-controlled trial. The mean total bodyfat dropped by 9%, moreover, the volume of visceral adipose tissue (stomach) decreased by 17%, whereas no changes were seen in the placebo group.

No Increase in Post Exercise Fat Utilization without Acute Exercise Increases in GH

 Since there is a delay in GH’s effect on fat metabolism, back in 2005 researchers wanted to see exactly what acute increases in GH did too fat metabolism after exercise so they gathered some test subjects and had them cycle @ 70% of their peak exercise capacity.  Post exercise fat metabolism was directly related to the acute rises in GH that occurred during the exercise protocol⁶.  Based on the study, the best way to increase your fat metabolism post exercise is to increase your GH.  It is well established that prolonged rest periods (3-5 minutes) result in very small rises in GH compared to taking short rest periods which leads to large increases in GH.  Is there any metabolic advantage of the large increases in GH that occur with short rest periods for increasing fat metabolism? According to a new study, the acute increases in GH may are essential for increasing post exercise fat utilization.  Here was the study design.  Researchers had subjects exercise for 1 hour, one group served as a control group while one group of subjects received a infusion of Octreotide (a potent inhibitor of growth hormone) which as an injectable formulation for the treatment of acromegaly (GH excess).  The control group had a fourfold rise in GH while the group receiving Octreotide had a blunted GH response during exercise.  Researchers found that post exercise fat utilization in subcutaneous adipose tissue were increased due to GH while it remained unchanged in the group receiving the drug that blunted GH responses during exercise⁴.  Researchers suspect the reason GH peaks about 2 hours after an intense bout of exercise is that glycogen needs to be replenished during that time so high levels of GH increase fat mobilization sparing glucose to be incorporated into glycogen.  So if you are looking to get ripped up, in addition to diet, large increases in GH from high intensity exercise may facilitate this process. 

GH has Direct and Indirect Actions on Fat Burning

The fat burning properties of GH are well documented.  Studies in fat cells and in human and animal models have shown that in addition to its direct lipolytic (fat burning) effect on adipose tissue (demonstrated by stimulation of basal fat lipolysis)^17,18,19.  GH can also increase fat loss by blocking fat storage.  11ß-HSD1 converts the inactive glucocorticoid, cortisone, to active cortisol in adipose tissue; 11ß-HSD1 is highly expressed in human adipose tissue³¹, and overexpression in adipocytes in a rodent model leads to a centrally obese. It has shown that exogenous GH is able to inhibit 11ß-HSD1 activity in patients with simple obesity which means GH blocks cortisol from binding to the adipose tissue receptor limiting fat storage³².  Small pulses of GH designed to mimic physiologic pulses, have been shown to induce a dose-dependent stimulation of fat oxidation and increase circulating levels of FFA and glycerol¹⁰.  In normal subjects, the onset of exercise leads to a 3-fold increase in the rate of fat oxidation and a rapid increase in uptake of free fatty acids into skeletal muscle where fat is burned as a fuel source¹³. It seems GH’s biggest impact on fat metabolism is during the post- exercise period.  For example, fat oxidation was studied in GH deficient subjects during and following discontinuation of long-term GH replacement. Discontinuation of GH was not associated with any change in fat oxidation at rest, but resulted in a marked reduction in fat oxidation and fatty acid release into the circulation during and following exhaustive exercise¹⁴. In a similar study, GH deficient adults who were receiving long-term GH replacement on 2 separate days, once with and once without a bolus of GH administered intravenously at the start of exercise. The protocol resulted in an increment in circulating GH levels during exercise that was indistinguishable from that seen in healthy normal subjects. Under resting conditions there was no effect of GH, while during and following 45 minutes of exercise at lactate threshold there was a greater fat oxidation following GH administration¹⁵.

GH and Catecholamines: The Fat Burning Combo

Adipose tissue lipolysis increases during exercise. The major stimulus for the enhanced lipolysis seems to be circulating catecholamines in combination with a low insulin concentration. Just all about all the major Fat Burners and thermogenics increase catecholamines for fat loss.  These supplements essentially mimic the actions of norepinephrine and epinephrine in a direct and indirect manner.  Directly, agonists activate beta adrenoreceptors (β-AR) and indirectly, they facilitate the release of epinephrine and/or norepinephrine (catecholamines). Catecholamines activate cAMP production and stimulate fat metabolism through β-AR stimulation and inhibit the process through α2-AR activation⁸.  Fat cell responsiveness to catecholamines depends on the ratio and functional balance between β - and α 2- receptors located on fat cells, which are influenced by sex, anatomical location of the fat depot, and obesity⁹. The lipolytic effects of epinephrine, which exhibits the highest affinity for the α 2-AR⁹. So how does GH influence catecholamines?  GH enhances the actions of catecholamines.  One study reported that when GH is added to fat cells, the addition of GH increased the fat cells response to epinephrine ( a powerful fat burning hormone)¹⁸.  Further studies have reported that GH results in an up-regulation of ß-adrenergic receptor density on fat cells^29,30. Although both catecholamines and GH work together, GH still outperforms catecholamines in terms of post-exercise fat utilization.

In 2000 researchers studied the response of GH and catecholamines during and following exercise of varying intensity and related these responses to changes in fat oxidation. During exercise, neither glucose utilization, which was directly proportional to exercise intensity, nor fat oxidation, which remained constant, was influenced by either GH or catecholamines during exercise. Fat oxidation following exercise was related to exercise intensity and while it correlated to both the peak GH and peak epinephrine response; after further analysis only the peak GH response was found to be the greatest predictor of post exercise fat utilization¹⁶. There is evidence, therefore, that endogenous GH secretion exerts an immediate as well as a delayed effect to increase fatty acid availability following exercise.