Most trainers and gym-goers would have heard of growth hormone and know of its importance in strength gains and fat metabolism.

Studies show that intense aerobic and resistance training is one way to stimulate growth hormone secretion. However, it would be great to increase the amount of growth hormone levels every time you train.

Studies have shown the majority of growth hormone secretion occurs at night and a number of other studies have shown that day time secretion in relatively low. Here in lies the question – how do we boost growth hormone levels during the day in order to provide more muscle growth and fat loss?

One particular study has shown that supplementation with GABA (Gamma Aminobutyric Acid) is the answer.

GABA is an amino acid and classified as a neurotransmitter. As a supplement, GABA has been shown in a number of clinical trials to consistently raise GH levels. Even though GABA is effective at increasing GH levels, no studies had examined the effect of combining GABA with intense exercise until recently.

The results of one particular randomised, double blind cross-over study were quite interesting. In this study, 11 healthy, resistance trained men participated in 4 experimental trials – 2 x resting and 2 x exercising. The exercise was short duration intense weight lifting. Each trial was separated by one week and just before each trial began the participants were given 3g of GABA or a placebo. Blood samples were analysed 90 minutes after administering the dose and GH levels tested.


The following were the findings:

– At rest, a 3g serve of GABA increased GH levels over that of the placebo by 375%.

– Weight training alone elevated GH levels. When combined with GABA, levels increased by 175% over that of weight training alone. So exercise increased GH levels, GABA supplementation further enhanced this effect.


What this means is that it is clear a dose of GABA is very effective in increasing GH levels, particularly during the day when normal secretion is low. It also shows that when you perform intense training, you can be assured of a nice spike in GH levels. To further enhance this, a dose of GABA will increase these levels dramatically.
Finally – the participants in this study took GABA first thing in the morning on an empty stomach. Therefore, to ensure maximal response, take a serve when you wake up. That way when you hit the gym for your morning workout, you can be assured of maximal GH response from training.


Powers ME, Yarrow JF, McCoy SC, Borst SE. Growth Hormone isoform responses to GABA ingestion at rest and after exercise. Med Sci Sports Exerc. 40, 104-10, 2008
Prepared by Brett Morris ISSN-SNS, Transformation Specialist at All Body Transformations on the Gold Coast. Registered Personal Trainer, Transformation Specialist & Certified Sports Nutrition Specialist with the International Society of Sports Nutritionists.