Nitrogen balance and muscle growth
What is nitric oxide?
Nitric oxide is a very small molecule (gas) produced locally in most cells of the body. It has become very popular recently, thanks to viagra, a drug that is among others a pharmaceutical booster NO. If nitric oxide can make you bigger and harder in a very strategic region, does it have the same effect on skeletal muscles?
Know that NO is constantly synthesized by your muscles, so it must somehow affect them. Numerous studies suggest that nitric oxide has a significant effect on muscle growth.
Nitric oxide and basal muscle anabolism
Most studies on the effect of NO on muscle have been conducted in animals. It is proved that the human muscles respond to the actions of NO in a similar way. In their experiments, the researchers used two options: temporarily blocking the release of nitric oxide with pharmaceutical inhibitors, or temporarily enhancing it by applying NO boosters.
When nitric oxide production was blocked in rats, it led to a rapid decrease in the level of protein synthesis in skeletal muscles - by almost 15%. The scientists concluded that NO "is responsible for maintaining the optimal level of protein synthesis in skeletal muscles." In other words, while not a hormone, nitric oxide is a fairly important anabolic factor.
NO and training with weights
During contraction and stretching, the muscles produce more and more NO. On the other hand, with a sedentary lifestyle, its production decreases. Regular training increases the ability of muscles to produce nitric oxide, thanks to the increased release of NO-synthetase (NOS), an enzyme responsible for the transformation of arginine (the main precursor of NO) into nitric oxide itself.
So what does increased NO production affect?
After overloading the muscles in rats, the processes of their hypertrophy begin after a while, but if you block the production of nitric oxide, this response is suppressed. In trained rats, the size of the target muscle increased by 76% after two weeks. Rodents treated WITH no blocker showed only 39% increase in muscle size.
It is obvious that not only nitric oxide is responsible for hypertrophy in response to exercise (since its suppression still did not stop growth completely). However, research results have clearly shown its main effect on muscle building processes, since the suppression of NO inhibits growth by almost 50%. This means that to ensure maximum anabolism, you must optimize the production of nitric oxide.
What is the reason why NO can have such a significant growth effect? Recent research explains the magical anabolic properties of this substance.
NO and IGF-1
Insulin-like growth factor 1 (IGF-1) is one of the main, if not the most important, anabolic hormone. It regulates many of the anabolic effects of growth hormone and some important functions of testosterone, playing a key role in muscle building processes. Regular training with weights not only increases the local level of IGF-1 in the muscles, but also increases the density of IGF-1 receptors in them.
However, without nitric oxide, IGF-1 loses most of its anabolic power, which means that the effect of training on the level of IGF-1 in the muscles is reduced. In other words, in order for IGF-1 to work, NO must be present.
NO and IGF anabolism
In one study, researchers gave NO TO adults who did not eat during the night, and then examined them six hours later. Before subjects received IGF-1, their muscles were in a catabolic state. IGF-1 converted them to an anabolic state, reducing the degradation of muscle protein by 46% and increasing anabolism by 50%. When scientists injected nitric oxide inhibitors with IGF-1, the results were not very good. The anti-catabolic effects of IGF-1 "did not notice" the lack of NO, but the anabolic effects were reduced by half. These results suggest that nitric oxide serves as an important mediator of IGF-1 anabolic actions in the human body - it is a key anabolic molecule if we are talking about muscles.NO and the release of IGF-1
Even more interesting is the role of NO in the training-induced release of IGF-1. Without the release of this growth factor, the impact of weight training on strength and muscle mass will be very modest at best. In one experiment, scientists overloaded the muscles of rats, with one group receiving NO inhibitors, the other a placebo. In the latter group, local IGF-1 release increased 2.4 times. There was no increase in IGF-1 levels in the muscles of rats with blocked NO. This and other studies show how important NO IS for both IGF-1 production and anabolic effects.
NO and satellite cells
Your cells need stem cells and amino acids to grow. The most important stem cells in our body are called satellite cells. They are located at the ends of muscle fibers, and proper training can activate them. However, studies have shown that if satellite cells were destroyed before the muscles were overloaded, they will not grow in response to stimulation. Therefore, satellite cells play a key role in muscle regeneration and growth. Scientists did not know which signal controls the activation of satellite cells, but using nitric oxide blockers, they found out that it serves as the main activator. Without NO, activation of satellite cells is not possible.
NO and HGF
Hepatic growth factor (HGF) is involved in muscle building processes. After intensive training with weights, it is released locally in the muscles, where it participates in recovery processes. The presence of HGF is very important for the activation of satellite cells. Thanks to nitric oxide blockers, we know that NO is necessary for post-training HGF release.
NO and tendons
NO is also needed to repair and strengthen tendons. When they are damaged, the local release of NO increases significantly. Research has shown that pharmaceutical nitric oxide inhibitors inhibit regeneration processes. Recent experiments suggest that artificially adding additional NO to a damaged tendon accelerates its recovery. And here we come to an interesting question: "Is it true that the more NO, the better?"
After learning about all the anabolic effects of NO described above, bodybuilders can assume that the more of IT, the better. Pharmaceutical nitric oxide boosters have already taken their place in the Arsenal of many athletes who are fond of chemistry.
Unfortunately, NO has one big drawback - it acts like a free radical. Therefore, despite all its anabolic properties, it also has catabolic properties. In fact, excess nitric oxide can destroy the muscle cell. A similar double effect was demonstrated by a recent study. Scientists over-stretched rat muscles to cause injury, with one group receiving a NO inhibitor. This significantly reduced the degree of injury compared to the other group, where nitric oxide was released naturally. However, three days after the injury, it became clear that the degree of regeneration was higher in the placebo group, despite a more pronounced initial catabolic response. So, at least up to a certain point, NO had more of an anabolic than a catabolic effect.
In their research, scientists not only suppressed the production of nitric oxide, but also tried to increase it to see how additional NO affects muscle protein synthesis. In the latter case, muscle anabolism increased only slightly - less than 3%. This increase is not statistically significant, and can be interpreted as the absence of the effect of additional NO or the inability to determine it due to a small number of experimental animals. However, the reasons for muscle growth in sedentary rats are not very much, but trained rodents are another matter. And, in addition, if weight training makes your muscles produce more nitric oxide, it's because the stimulated muscles need more NO.
One study found that when stimulated to raise nitric oxide levels, subjects immediately became 5% stronger if the NO level was higher than normal. So, for some bodybuilders, extra NO may be useful, at least before training.
Optimization of NO secretion
Instead of raising the NO level very high, as your "chemical" colleagues do, you should strive to optimize the natural release of nitric oxide in order to ensure maximum anabolism and minimal catabolism. Research shows that this is not always easy to do. Regular training can raise the level of NO in the muscles, however, everything is not as simple as it seems. For example, cortisol, a well-known catabolic hormone whose release also increases after exercise, can slow down the production of nitric oxide by suppressing the activity of NO-synthetase. Moreover, with age, the muscles synthesize less and less NO, so you will have to look for some other natural means to activate this process.
The first natural NO booster is arginine. Research has shown that arginine increases the production of nitric oxide in humans, but taking just one of them will not be effective for everyone. Some people have difficulty with the absorption of arginine. In one study in which subjects took large doses of arginine orally (6 grams), it was found that only 68% of the amino acid was absorbed by the gastrointestinal tract. In some people, this figure reaches 100%, while others are able to absorb only 50%. Of course, if you are one of the latter, the effect of taking arginine will be negligible.
To enhance the effects of arginine, you can drink cranberry or red grape juice, as they stimulate no synthesis in other synergistic ways. Vitamins C, E and A also have a beneficial effect on the synthesis of nitric oxide, so you can take them along with other antioxidants and arginine. As you can see, NO can be classified as an anabolic molecule. Its effect on muscle building is much more important for bodybuilders than for ordinary people, because nitric oxide plays a significant role at the very beginning of the processes of muscle regeneration and growth after training.
