Silk Amino Acids for swimmers
Supplementation with high doses of Silk Amino Acids may boost swimmers' endurance capacity. Sports scientists from Gdansk in Poland write about this in the Journal of the International Society of Sports Nutrition. Silk Amino Acids inhibit the increase of lactic acid in high-performance swimmers.
Silk Amino Acids
Manufacturers make Silk Amino Acids from the cocoons of the silkworm Bombyx mori. The proteins in these cocoons consist mainly of alanine and glycine, but also of serine, valine and threonine. Sports supplements manufacturers market Silk Amino Acids as products that have been shown (in animal studies) to boost testosterone levels and endurance capacity. The industry also claims that Silk Amino Acids speed up post-exercise muscle recovery.
So far there have been no human studies on the effects of Silk Amino Acids. The Polish study is the first.
The researchers gave 12 male finswimmers a portion of Silk Amino Acids three times a day during a 12-day long training camp. The men trained three times a day and were given their Silk Amino Acids, dissolved in water, 30 minutes before each training session. The men consumed a daily total of 0.5 g Silk Amino Acids per kg bodyweight.
A control group of 12 men took a placebo.
The researchers got the men to swim as fast as they could and then measured the amount of lactic acid in their blood afterwards. Measurements were also taken before and after the supplementation period. The first figure below shows that there was little change in the placebo group. The second figures shows how the supplementation seemed to reduce the amount of lactic acid produced. Because a too high concentration of lactic acid inhibits high-intensity exercise the Poles think that Silk Amino Acids can help extend endurance capacity.
Silk Amino Acids indeed appeared to increase the testosterone concentration in the swimmers' blood - a little bit - but also increased the cortisol levels.
The concentration of creatine-kinase in the blood of the swimmers also rose, which suggests that the supplementation slightly increased muscle damage.
The researchers used an exceptionally high dose. Manufacturers recommend daily doses of several grams, not a several tens of grams – as the researchers used. The supplements manufacturers base their doses on formulas used to convert doses from animal studies into human doses.
The Poles consciously chose to use a high dose. They used the doses used in the animal study directly on people, which on the advice of the trainers were increased even further.
This study therefore probably doesn't give an accurate picture of what Silk Amino Acids can and cannot do.
Journal of the International Society of Sports Nutrition 2014, 11:57.
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