Growth Hormone Isoform Responses to GABA Ingestion at Rest and after Exercise.

Abstract:
Oral administration of the amino acid/inhibitory neurotransmitter gamma aminobutyric acid (GABA) reportedly elevates resting serum growth hormone (GH) concentrations.

Purpose: To test the hypothesis that GABA ingestion stimulates immunoreactive GH (irGH) and immunofunctional GH (ifGH) release at rest and that GABA augments the resistance exercise-induced irGH/ifGH responses.

Methods: Eleven resistance-trained men (18-30 yr) participated in this randomized, double-blind, placebo-controlled, crossover study. During each experimental bout, participants ingested either 3 g of GABA or sucrose placebo (P), followed either by resting or resistance exercise sessions. Fasting venous blood samples were acquired immediately before and at 15, 30, 45, 60, 75, and 90 min after GABA or P ingestion and were assayed for irGH and ifGH.

Results: At rest, GABA ingestion elevated both irGH and ifGH compared with placebo. Specifically, peak concentrations of both hormones were elevated by about 400%, and the area under the curve (AUC) was elevated by about 375% (P < 0.05). Resistance exercise (EX-P) elevated time-point (15-60 min) irGH and ifGH concentrations compared with rest (P < 0.05). The combination of GABA and resistance exercise (EX-GABA) also elevated the peak, AUC, and the 15- to 60-min time-point irGH and ifGH responses compared with resting conditions (P < 0.05). Additionally, 200% greater irGH (P < 0.01) and 175% greater ifGH (P < 0.05) concentrations were observed in the EX-GABA than in the EX-P condition, 30 min after ingestion. GABA ingestion did not alter the irGH to ifGH ratio, and, under all conditions, ifGH represented approximately 50% of irGH.

Conclusions: Our data indicate that ingested GABA elevates resting and postexercise irGH and ifGH concentrations. The extent to which irGH/ifGH secretion contributes to skeletal muscle hypertrophy is unknown, although augmenting the postexercise irGH/ifGH response may improve resistance training-induced muscular adaptations.

my only issue with this is the effectiveness this rise has on us, as indicated in the summary.

GABA has always been sold on the premise of HGH rise..but the rise, personally, is negligible for any real benefit in our world?.....

KP

it's funny actually cos I haven't heard about GABA (the supplement) in a long time. I tried it once at Uni about 12yrs ago and it didn't do much for me. And ESN is the first place I've seen it talked about again.

Glutamine, Glycine, Gammanol Forte with FRAC & Alpha-GPC are probably the best GH modulators.

I still believe it to be a bedtime (rest) supplement. I just posted this up as there was some debate the other day about using it pre workout.

kp1512 wrote:my only issue with this is the effectiveness this rise has on us, as indicated in the summary.

GABA has always been sold on the premise of HGH rise..but the rise, personally, is negligible for any real benefit in our world?.....

KP

I like GABA for reasons beyond the hGH benefit... the relaxing but not activity inhibiting effect of the stuff is really quite nice. Have never used it around training sessions, but do think it works well as a pre-bed supplement.

It can also work well as part of an anti-headache stack - 5g GABA, 5g AAKG and 5g Taurine kills a mild-moderate headache (takes around 30-45 mins to work) much better than paracetamol or codine (for me anyway). It's also very cheap .

I've used GABA on and off over 8 years or so and have always been a fan.

Seem to sleep better for it and look a little sharper with it.

I have used it pre workout but not long enough to work out if there's any benefit. I'm sure with my current stack any benefit would be lost.

Alex wrote:I've used GABA on and off over 8 years or so and have always been a fan.

Seem to sleep better for it and look a little sharper with it.

I have used it pre workout but not long enough to work out if there's any benefit. I'm sure with my current stack any benefit would be lost.

Yes, when taking every night for a few weeks I always seem to find my definition improves slightly. I also agree that if stacking the stuff, you do need to stick to just a few other simple aminos. Taking it at the same time as casein or with a source of carbs seems to render the stuff totally ineffective/make it bio-unavailable.

And normaly any insulin secretion may have a negative effect on the HGH secretion that's why I ve done something that seem stupid in term of anticatabolism.

I am waiting to be hungry before bed and then take between 5 and 10 grams (not really scientific the 5-10 !) and go to bed.

I recover better and apparently my BF level decrased and it seems to be obvious, my Girlfriend told me, my abs look great. before they were simply OK

I'll keep doing this for at least one month to see if I really have some benefits in term of body composition alteration.

Hugh wrote:And normaly any insulin secretion may have a negative effect on the HGH secretion that's why I ve done something that seem stupid in term of anticatabolism.

I am waiting to be hungry before bed and then take between 5 and 10 grams (not really scientific the 5-10 !) and go to bed.

I recover better and apparently my BF level decrased and it seems to be obvious, my Girlfriend told me, my abs look great. before they were simply OK

I'll keep doing this for at least one month to see if I really have some benefits in term of body composition alteration.

I'm wondering if you could eat your bedtime meal, then down some R-ALA to nuke any insulin response then take GABA and get the best of both worlds.

Or am I taking pish again?

cleaver wrote:

Hugh wrote:And normaly any insulin secretion may have a negative effect on the HGH secretion that's why I ve done something that seem stupid in term of anticatabolism.

I am waiting to be hungry before bed and then take between 5 and 10 grams (not really scientific the 5-10 !) and go to bed.

I recover better and apparently my BF level decrased and it seems to be obvious, my Girlfriend told me, my abs look great. before they were simply OK

I'll keep doing this for at least one month to see if I really have some benefits in term of body composition alteration.

I'm wondering if you could eat your bedtime meal, then down some R-ALA to nuke any insulin response then take GABA and get the best of both worlds.

Or am I taking pish again?

You could...but it may take a good 60+ mins...

whenever you eat why not take some omega-3s instead. They'll limit the insulin spike from any type of food

health4ni wrote:whenever you eat why not take some omega-3s instead. They'll limit the insulin spike from any type of food

Id have to disagree with this....the spike-limiting aspect would be limited anyway, but taking something like dextrose, WMS or any hi GI carb will be just as bad with O3 as without....

1. Omega-3s block sugar absorption, therefore they mitigate the insulin response
2. Never take omega-3s with a post workout shake, so the example you give is irrelevant. This is the one time you do want a big insulin spike.

health4ni wrote:1. Omega-3s block sugar absorption, therefore they mitigate the insulin response
2. Never take omega-3s with a post workout shake, so the example you give is irrelevant. This is the one time you do want a big insulin spike.

to what degree...I am assuming this is extremely minimal?..and in this context maybe so remote that its effects overall dont merit consideration?

KP

I was told that it is quite a good insulin limiter (so to speak). But I have no research at the mo to back this up.

Thus, the more obese a person is the better it is to have omega-3s with each feeding.

It certainly makes you more insulin sensitive though.