Injectable HGH was developed in the mid 1980’s, and was available to the public in the 1990’s. People who buy HGH injections today are fully aware that it has been on the list of forbidden substances since it became available in its recombinant form.
Although its effectiveness in enhancing physical performance has been questioned over the years, injectable HGH injections are used for its potential anabolic effect on muscle growth and cell regeneration. The degree of similarity between the endogenous and recombinant forms of injectable HGH injections, and the secretion and marked variability makes for detection of doping very difficult in athletes.
There were two approaches proposed to overcome this problem of detecting injectable HGH in an athlete, one being the indirect method which measures a combination of several factors in the biological cascade affected by taking injectable HGH injections. Number two is the direct method which measures the difference between the recombinant and the circulating forms of injectable human growth hormones.
The main effects of exercise in athletes, increases the natural human growth hormone production in the human body, which is produced by the pituitary gland that sits inside of the brain. This is where the difficulties encountered by laboratories when they try to prove misuse of this substance by either direct or indirect analysis are emphasised. The direct method seems to have the best reliability, even though the window of time for detection is far too short.
When athletes buy injectable HGH and take the HGH injections for doping purposes, it presents major challenges in the fight against doping in sports. So the effects that exercise has on injectable HGH, and its short half-life span, are still presenting many difficulties during the doping analysis in athletes. So far the most promising method appears to be the direct approach that utilises immunoassays.
The use of injectable HGH injections in sports today is not only based on its anabolic properties, but also its effect on carbohydrate and fat metabolism in the body. For the first time ever, they started testing using the direct method at the 2004 Olympics in Athens. None of the positive serum samples were declared positive because of the detection time window being far too short of the test.
The short half-life of injectable HGH is only about 20 minutes at best. Many studies have shown that human growth hormone concentrations returned to baseline 8-16 hours after any intramuscular injections, and 12-20 hours after subcutaneous injection. After many studies doctors realised that the concentration of human growth hormone in the body increases with time for any given work intensity, and can increase up to 10 fold with prolonged moderate exercise.
During more intensive exercise, like when training above the lactic threshold for any period of time, will generally amplify the pulsatile release of human growth hormone, which will elevate the HGH amplitude.
It also appears that the injectable HGH response is more closely related to the peak intensity of exercise, rather than the total work output. There are other factors that can increase the injectable HGH secretion in the body. Secretion can be increased in hypoglycemia, increased temperature, stress. It also decreases in people who are obese, or eat a diet high in carbohydrates and intake of adrenergic agonists.
So this makes it very hard to differentiate between the increase in injectable HGH levels seen in exercise, and what can be seen from doping by taking injectable HGH injections.