From Ergo Log
Phosphatidylserine improves the body’s hormonal response to training. Men given a daily dose of 600 mg for ten days in a row produced more testosterone and less cortisol than men who didn’t take phosphatidylserine after fifteen minutes of exercise.
This was the conclusion that researchers at the University of Mississippi drew after performing an experiment with ten healthy men. The subjects had to cycle for fifteen minutes a couple of times, and also did five ‘sets’ of three minutes. Each ‘set’ started with a moderate level of effort – about 65 percent of the VO2max – and ended with 85 percent intensity. The researchers measured the concentrations of cortisol, testosterone, lactate and growth hormone in the subjects’ blood before and after the exercise. During one of the sessions the men took phosphatidylserine and during the other session a placebo.
Phosphatidylserine is found in the membranes of cells. When taken as a supplement it improves the receptors’ function and resistance to stress. Exactly how it works is not known, but small-scale human studies have shown that phosphatidylserine lowers cortisol concentrations after exercise and exposure to stress. That was the reasoning behind the research we’re talking about here. The researchers wanted to know whether they could improve hormonal response using a fairly simple supplement. After all, less cortisol and more testosterone means more progression.
The researchers were lucky. The supplement reduced the cortisol production, as the figure below shows.
Taking the supplement also increased testosterone production.
Sports scientists often use the ratio between cortisol and testosterone as an indicator of how easily the body builds up muscle. That’s why some sports scientists advise athletes to do power training early in the evening: testosterone levels may well be somewhat lower than earlier in the day, but cortisol levels are radically lower at this time of the day. The figures below show how the cortisol-testosterone ratio changed as a result of taking the supplement. The black bar represents the group that took phosphatidylserine.
The figure on the left shows the effect on the total amount of testosterone in the blood during the experiment. The black bar represents the group that took phosphatidylserine, and the total amount of testosterone increased by 35 percent in this group. The middle figure shows the effect on the total amount of cortisol, which is 35 percent lower in the phosphatidylserine group. The ratio between the two hormones improved by at least 180 percent.
The researchers found no effect on the concentration of lactate in the blood, and statistically speaking phosphatidylserine had no significant effect on the growth hormone levels. But looking at the curve you’d be forgiven for thinking differently. Oh well, you can’t have everything.
Phosphatidylserine is found in lecithin, but you’d have to take an awful lot of lecithin to reach the dose used by the researchers. One hundred grams of lecithin contains about fifteen milligrams of phospholipids, and only a small amount of these is made up of phosphatidylserine.
J Int Soc Sports Nutr. 2008; 5: 11.