Scope of application of additives
Rough estimates of the use of supplements show that some athletes regularly consume a huge amount of various supplements in doses far exceeding the safe threshold. At the same time, most of them believe that the so-called natural dietary supplements are safe. However, their long-term consumption in large doses can be harmful to health ( first of all, we are talking about the consumption of dangerous amounts of iron, zinc and other metals).
When using additives, the following reasons are usually mentioned:
- they compensate for an unbalanced diet;
they help to achieve increased requirements during heavy training or frequent competitions;
they allow you to keep up with the rest of the team members or rivals;
they are recommended by a coach, parents or other close people.
Athletes continue to take dietary supplements, even if, based on a biochemical analysis of the diet, it becomes known that their standard regimen is adequate or that the reserves of substances, for example iron, are normal.
Increasing strength: stimulating tissue growth and repair
A large number of such supplements are sold under the guise of” anabolic “or” anti-catabolic ” agents that have a direct or indirect effect on the synthetic metabolism of proteins in the muscles.
The proposed mechanisms of action include influencing the pathways of metabolism by increasing the availability of amino acids, stimulating the release of hormones or enhancing hormonal action.
Among the additives from this category are amino acids, boron, chromium, chrysin (yellow pigment from poplar buds), colostrum, creatine, hydroxymethylbutyrate( HMB), ornithine-alpha-ketoglutarate, proteins, creeping anchors, vanadium and zinc.
Despite the fact that protein products are the most popular of this group, a significant place is also occupied by sales of creatine (a product used only in sports nutrition) and some other supplements.
Proteins and amino acids
Athletes often claim that an increased amount of protein is necessary for them to increase muscle mass, but literary sources do not confirm this hypothesis. This apparent inconsistency can be explained by Milward’s adaptive model of metabolic needs, which assumes that the body adapts to either high or low consumption and that such adaptation to change occurs very slowly. With a high protein intake, an increased regulation of protein breakdown and the oxidation of amino acids begins. With a sharp reduction in protein intake, an athlete who is accustomed to high protein levels experiences a loss in muscle mass before reaching balance.
Prohormones and related compounds
It was found that the consumed “testosterone prohormones” slightly increase the level of testosterone in the blood of young men and do not increase the strength or size of muscles. These dietary supplements can pose a significant threat to health and cause a positive reaction to doping control.
According to experts, many herbal supplements increase the concentration of testosterone and, therefore, have an anabolic effect. These include tribulus terrestris, chrysin, indole-3-carbinol, So palmetto, gamma-oryzanol, iohimbine, sassaparil and mumie. All these statements are based on data obtained in the laboratory. Recently, it was proved that drugs containing tribulus terrestris, crisin, indole-3-carbinol, palmetto together with androstenedione or androstenediol do not increase the concentration of testosterone and do not affect muscle growth compared to strength training (Brown et al., 2000a, B, 2001a, B). Available clinical data show that such plant extracts have no value.
Stimulation of energy sources
Dietary supplements that increase performance through enhanced energy supply and fatigue control include bicarbonate, caffeine, car-nitin, creatine, guarana, hornet juice, iron, magnesium, pyruvate and ribose. It should be noted that the work of not all of these dietary supplements is confirmed by experimental data. There are reasons to believe that in some situations, taking bicarbonate, caffeine, creatine is useful for some athletes.
Several studies have studied the effect of antioxidant supplements on the coefficient of muscle damage caused by the action of free radicals during physical exertion, and there is evidence of the protective effect of supplements (Kanter, 1995; Dekkers et al., 1996). The data show that taking supplements can weaken the signs of muscle damage, but there is no evidence of a beneficial effect on performance. Negative effects of additives are also possible, since some of them can act as oxidation accelerators (pro-oxidants). Toxic effects of large doses of additives are unlikely, but there is a possibility of adverse consequences of prolonged use of large doses of additives of one antioxidant. One study reported an increase in the degree of muscle damage during exercise after taking ubiquinone supplements. It is well known that many food antioxidants in large doses can act as pro-oxidants.