What does muscle growth depend on? First of all, of course, from the work of hormones – insulin and testosterone. In addition, insulin-like growth factor (IGF-1) is involved in the process. By the way, some people suggest that in creating an anabolic effect, IGF-1 performs even more important functions than insulin itself.
However, all this has long been known. But recently scientists made a new discovery: it turns out that amino acids can also cause anabolic and anti-catabolic effects!
This question was studied by a group of experts at the University of Gothenburg in Sweden. Eight healthy athletes served as “experimental subjects”. To begin with, the scientists measured their synthesis (growth) and degradation (breakdown) of microfibrillar (involved in muscle contraction) and globular proteins (which are not directly involved in muscle contraction). And then they began to administer amino acid mixtures of different concentrations intravenously. And what did the tests show? The content of amino acids in the blood of the subjects constantly increased. But plasma levels of glucose, lactic acid, insulin and IGF-1 remained unchanged. In addition, the researchers monitored the absorption and processing of these substances in the muscle tissue of the arms and legs. And again, they did not find any changes in the metabolism of glucose and fats. But amino acids were absorbed by muscle tissue in huge quantities. Thus, amino acid infusions directly stimulated the synthesis of microfibrillar and globular proteins, the very ones that give rise to “mass” growth. Moreover, the post-workout catabolic breakdown of muscle proteins noticeably decreased.
What follows from this? Here’s what: as it turned out, the anabolic effect of amino acids can occur independently of insulin and IGF-1! In other words, insulin is not needed for amino acids to get into the muscles. Insulin, which many experts consider to be perhaps the most important anabolic hormone, actually rather acts as an anti-catabolic. As for IGF-1, it is not as fundamentally important as some researchers believe.
Now we know that it is possible to stimulate muscle growth without external help – without an “infusion” of insulin, testosterone and growth hormone. Amino acids themselves are excellent anabolic steroids! And they don’t need hormonal help. But quite recently the opinion of sports specialists was the opposite. Amino acids were considered only the raw materials of anabolism, which are used only after injections of steroids, GH and insulin. It turned out that amino acids are an independent anabolic factor, which means that those who do not want to take “chemistry” have an equivalent solution.
