A special type of fatty acids derived from soybeans can improve resistance to exercise, according to Medicine and Science in Sports and Exercise (2006; 38: 64-71). Men who took phosphatidyl serine for 10 days were able to perform high intensity exercise for longer than those who took placebo. Research suggests a new application for this supplement that is known primarily for its support for cognitive function and memory.
Fourteen healthy men participated in the double-blind trial, which consisted of two exercise tests. In each test, the men completed 3 periods of 10 minutes of exercise bike at calculated rates to bring them to 45, 55 and 65% of their maximum oxygen consumption, followed by a final exercise that required 85% and that continued until they were exhausted. All periods of exercise were separated by 5 minutes of rest. After 5 days of recovery, they began a 10-day supplementation either with phosphatidyl serine (750mg per day) or with placebo. On the eleventh day, the second exercise test was carried out, which was identical to the first.
The men who took the phosphatidyl serine supplement significantly increased their ability to exercise compared to those who took placebo. On average, the group that took phosphatidyl serine took two minutes longer to reach exhaustion than before supplementation. Those who took a placebo did not experience any change in exercise capacity.
Phosphatidyl serine is a natural phospholipid. Phospholipids are important parts of cell membranes. They are composed of a hydrophilic part (phosphate) and a hydrophobic part (lipid). These properties help to define the structure of biological membranes and allow the movement of materials into and out of the cells. Phosphatidyl serine naturally concentrates in organs with high metabolic activity. Its main functions are to help maintain a correct balance of minerals in tissues and stimulate certain enzymes involved in energy metabolism.
The mechanism by which phosphatidyl serine improved resistance is not known. However, given its known functions in the body, it is suggested that the supplement delayed the onset of fatigue by maintaining calcium, sodium and potassium levels in skeletal and cardiac muscle tissues for a longer period of exercise.