Soy protein and key components for sports performance

Soy protein is a high quality protein comparable to milk protein. In addition to containing all of the essential amino acids (building blocks of protein) required by children over two years of age and adults, it contains several amino acids namely arginine and glutamine ¹⁰ , that are important for sports performance.

Soy and Arginine

Arginine plays a key role in stimulating the release of hormones that promote muscle formation, and is required for the formation of a compound known as 'creatine phosphate', which is one of the most important sources of energy for muscles ¹¹ , ¹² , ¹³ . For athletes, arginine may play a key role in muscle formation, blood vessel health and in helping to maintain a strong and healthy immune system ¹³ .

Soy and Glutamine

Glutamine is an amino acid that is considered essential during metabolic stress. Glutamine promotes protein synthesis and improves immune function ¹² , ¹⁴ . Even more important for the athlete, glutamine helps to maintain adequate hydration in cells and buffers the lactic acid that builds up during exercise ¹⁵ . These functions of glutamine help to support performance and recovery. Soy protein foods are also a good source of the amino acids leucine, isoleucine and valine, which are used as an energy source during exercise ¹⁰ , ¹⁶ .

Many soy foods provide significant amounts of the mineral iron, which is beneficial to exercise performance and general health. A common problem experienced by athletes is "sports anaemia", which is believed to be due to intense training ^17-19 , loss of iron via sweat and urine and the actual destruction of red blood cells with increased temperature and mechanical trauma caused by pounding of feet on running surfaces ^20-23 . Female athletes have an even greater risk of "sports anaemia" due to iron losses through menstruation. Recent studies have shown a beneficial role for soy protein when used as a supplement to improve iron status ¹ .