After a busy working week in the gym, the prospect of drinking a glass of good wine or a mug of cold beer to relax is very tempting. At the same time, of course, you want not to lose anything you earned by the sweat of your brow in the gym. Unfortunately, scientific evidence shows that drinking alcohol slows muscle development, so you often face a dilemma about whether to drink. More detailed studies have shown that the negative effect of alcohol on muscle development depends on the dose. More alcohol means more weight loss.
Anabolic reactions within muscle tissues occur due to the difference between the amount of newly synthesized proteins and the scale of a breakdown of proteins that have already accumulated in the muscles. The higher the level of protein synthesis, the more significant the increase in muscle mass. These processes can increase by excessive alcohol consumption, negatively affecting protein synthesis and muscle development. One study demonstrated that in muscle cells exposed to alcohol, sensitivity to insulin stimulation and IGF-1, that is, factors that induce protein synthesis, decreases by 30% and 60%, respectively.
In addition, this study showed that alcohol does not affect the rate of degradation of muscle tissue, which proves that alcohol affects muscles only negatively by suppressing protein synthesis. In addition, another study showed that alcohol directly disrupts protein synthesis stimulated by the transmission of mTOR signals. This effect is due to the ability of alcohol to block the production of phosphatidic acid by the enzyme phospholipase D, located inside the cells. Phosphatidic acid is a molecule known to activate the mTOR pathway directly in response to strength training. Consequently, a decrease in the level of phosphatidic acid under the influence of alcohol reduces mTOR-activated protein synthesis, which leads to a reduction in the rate of muscle development.
Alcohol inhibits the growth of fast-growing fibers.
In the human body, there are two different kinds of muscle fibers: fast and slow. The names are from the speed at which these fibers contract, with fast-shrinking threads doing so about four times shorter than slow-shrinking fibers, giving them tremendous energy generation potential. Moreover, fast-spinning fibers are much larger than slow ones. Since fast-spinning fibers are much larger and more robust, they respond better to strength training and are responsible for increasing strength and muscle mass.
The fast-growing fibers suffer the most from the effects of alcohol in a study in which alcohol-injected rats showed a decrease in protein synthesis in muscle tissues, especially in fast-twisting threads. These results indicate that alcohol consumption is most likely to lead to a reduction of muscle strength and mass due to the adverse effects of alcohol on rapidly contracting muscle fibers.
Alcohol increases myostatin levels.
Studies have also shown that alcohol increases a muscle-destroying substance known as myostatin, which further impairs muscle development. Myostatin belongs to the family of beta-transforming growth factors (TGF-beta). Still, although it is a growth factor, it reduces muscle growth by blocking the formation of new muscle fibers and reducing the level of protein synthesis caused by the mTOR signaling pathway; demonstrated The negative effect of myostatin on muscles from alcohol consumption in a study. Showed that prolonged alcohol consumption (sixteen weeks) by rats increased the level of myostatin in muscle tissues. Moreover, higher myostatin levels led to a marked decrease in muscle protein mass in rats who consumed alcohol.
Excess alcohol creates a catabolic environment in the body.
Drinking alcohol can alter the level of the anabolic hormone testosterone, which also affects muscle development. This effect is dose-dependent; a small amount of alcohol can raise testosterone levels, and a large amount causes it to drop significantly. One study showed a positive impact of small doses of alcohol on testosterone production. The volunteers drank two servings of alcohol, which increased testosterone levels by 17%.
The study’s authors concluded that such an increase in testosterone levels might be associated with an increase in NADH (nicotinamide adenine dinucleotide) produced from metabolites of digested alcohol. NADH is a coenzyme produced by the body that plays a role in energy production. An increase in NADH levels increases the activity of the enzyme 17-hydroxysteroid dehydrogenase (17 beta-GSD), which catalyzes testosterone production. An increase in the movement of 17 beta-GSD leads to an increase in testosterone production.
Another study examined the effects of high doses of alcohol, about six to seven servings. This dose caused a drop in testosterone levels by an average of 23% when measured ten to sixteen hours after ingestion. So why do low amounts of alcohol increase the production of NADH and testosterone, while higher doses are unfavorable? There seems to be a threshold above which alcohol becomes toxic by damaging the cells in the testicles responsible for testosterone production, called Leydig cells.
This toxicity counteracts any positive effects of NADH overproduction. The toxic effect of alcohol on Leydig cells leads to a decrease in testosterone production. As if it’s not enough that high doses of alcohol lower testosterone levels, they also increase the level of the muscle-destroying hormone cortisol. The combination of a decrease in testosterone levels and an increase in cortisol levels due to excessive alcohol consumption increases the degradation of proteins in muscle cells, which means that alcohol in high doses does not go hand in hand with building strength and muscle mass.
