Glutamine is a supplement claimed to increase performance. Does it really? Let’s look into the science.
Glutamine is an Amino Acid
Proteins are made of 20 different amino acids, and glutamine is one of the so called non-essential amino acids, meaning the body can make its own and getting it from food isn’t a must. Long periods of heavy exercise have been linked to lowered levels of glutamine in the blood, and it was thought that this might be the cause behind weakened function and infection risk after exercise in athletes (2, 3).
Glutamine Put to the Test
To test this, we have to look at studies where people have been given glutamine (experimental studies). Results from these studies show no improvement in immune function. Furthermore, glutamine alone doesn’t affect muscle breakdown or carb storage (glycogen synthesis). Some short-term improvement in exercise capacity has been seen in patients with heart disease (7, 8), but NO benefit has been found when giving healthy, well-fed people glutamine (3, 4). Companies trying to sell you supplements will obviously cherry-pick studies where effects have been seen on sick people, but you need to consider the studies on healthy people like yourself.
Take Home Message
Save your money and stick to other supplements that work, like caffeine!