Growth hormone (GH, HGH) is produced by the pituitary gland, and its main functions are stimulation of growth and regulation of other bodily functions. During physical training exercises, HGH has been demonstrated to play an important role in increasing muscle mass and lipolysis simultaneously. Results from recent studies have revealed that alpha glycerylphosphorylcholine (A-GPC) can stimulate the production of GH during resistance training by catecholamine release. As such, a study was conducted to explore the role of an A-GPC supplement on growth hormone levels and workout performance.
Current Research On A-GPC
Methodology: A total of seven men with prior strength training experience participated in this study. The participants were then randomly assigned to either the A-GPC supplement group or the placebo group. Before a 90-minute workout, study participants consumed a 600mg A-GPC supplement or a placebo. The workout included half a dozen sets and ten repetitions of squats. Growth hormone levels were measured prior to exercise and at specific time increments post-exercise. Additionally, substrate oxidation levels (fat and carbohydrate) were measured 30-minutes post-exercise. Peak force and power were measured subsequently after oxidation levels by performing bench press throws.
Results: Data was analyzed using paired t-test and ANOVA. A p-value equal to or below 0.05 was considered statistically significant. Levels of growth hormone increased significantly in the A-GPC group (0.19 to 8.4 ng/mL) compared to the placebo group (1.9 to 5.0 ng/mL). At 15-minutes post-exercise, the A-GPC group had approximately double the growth hormone concentration of 8.4 ng/mL compared to 5.0 ng/mL for the placebo group. Moreover, the A-GPC group had a greater bench-press force compared to the placebo group (933N vs. 818N, respectively; p < 0.02). Although not statistically significant, associations in other parameters were observed in the A-GPC group, such as greater bench press power and reduced respiratory exchange ratio.
What Are The Implications Of these Findings?
The results of the study are promising as they demonstrate an increase in serum GH levels and peak bench press force after administering a 600mg dose of an A-GPC supplement before resistance training. However, the A-GPC group showed no impact on other parameters such as resting metabolic rate, cardiac function, and power. Prior research surrounding this topic has varied significantly in methodology and has stirred controversy due to the lack of consistent findings. Therefore, future studies should focus on verifying the results of existing studies by recruiting a larger sample size and investigating the effects of various doses on levels of Why Many Are Using HGH For Bodybuilding.