GABA Drastically Augments GH Release Post-Exercise

GABA (gamma-animobutyric acid) is an important neurotransmitter, found primarily in the brain, which plays a role in relaxation. While it’s uses as a sleeping aid are widely known, a recent study published in Medicine and Science in Sports and Exercise has found some interesting results, which may rapidly make GABA an extremely popular supplement within physical culture circles.


The researchers prefaced the study by stating that, while GABA administration has been shown to stimulate the secretion of Growth Hormone (GH) at rest, no studies have reported the effects of GABA ingestion on immunoreactive GH (irGH) after resistance exercise. The scientists hypothesized that GABA ingestion would increase circulating irGH and immunofunctional GH (ifGH) concentrations at rest and that administering GABA prior to exercise would augment the irGH/ifGH response to resistance training.

Their study used a randomized, double-blind, placebo-controlled, crossover study design to test their theory on eleven resistance-trained men (18-30yr). The participants ingested either 3g of GABA or a sucrose placebo (P), and then either rested or performed a resistance exercise session.

As theorised, at rest, GABA ingestion elevated both irGH and ifGH levels compared with the placebo. However, here is where the study gets interesting …

200% greater irGH and 175% greater ifGH concentrations were observed in the participants who exercised after taking GABA, in comparison to those who exercised using a placebo.

Practical Application:

So why would this be of interest to anyone? Well, GH is known to have a range of perks including stimulating fatty acid use and protein synthesis. As GABA apparently stimulates irGH / ifGH release, the researchers admit it is a possibility that the GABA thus induces lypolytic effects (fat-loss) and skeletal muscle protein accretion (lean mass gain). Another consideration is that GH may indirectly alter skeletal muscle protein synthesis by stimulating the circulation of IGF-1 (insulin-like growth factor 1), which is a mediator of muscle growth.

Naturally, more research needs to be done to determine the exact effects of GABA-induced GH secretion on fatty acid metabolism or muscle gain. However, the signs certainly do appear to be promising.

GABA-DABA-DOO!

Reference:

Powers, M. E., Yarrow, J. F., McCoy, S.C., & Borst, S.E. (2008). Growth hormones isoform responses to GABA ingestion at rest and after exercise. Med Sci Sports Exerc, 40(1), 104-110.